Autumn Root Vegetable Gratin with Herbs and Cheese

By Merrill Stubbs
September 30, 2014
70 Comments


Author Notes: I don't know many people who would turn down a potato gratin, do you? What I love about this classic dish, other than its near universal appeal, is that it is deceptively simple to make relative to its beauty. Plus, you can probably make it with what you have in your fridge and pantry right now.

My go-to gratin is the one I learned in cooking school; it relies on garlic-infused milk instead of cream, and the potatoes are thinly sliced and added to the baking dish raw. (I find par-boiled gratins are often grainy and/or mushy, and you can't layer the potatoes into the dish in as pretty and precise a pattern if you've already cooked them.) Other than the garlic, for flavor all you add is salt, pepper, and some Gruyère cheese -- that's it. You bake the gratin in a hot oven until the potatoes are tender and the milk thickens into a sauce, and you've got a gorgeous, versatile side dish.

After having relied on my old standard for over 15 years (yikes!), I decided to shake things up a bit. With all the lovely roots and tubers appearing in the markets, why not apply the same technique to a mix of vegetables? And maybe I could even throw in some herbs and switch up the cheese while I was at it.
Merrill Stubbs

Serves: 6

Ingredients

  • 1 1/2 cups whole milk
  • 2 cloves garlic
  • Pinch freshly grated nutmeg
  • 2 tablespoons extra virgin olive oil
  • 3/4 pound butternut squash
  • 3/4 pound white potatoes
  • 1/2 pound parsnips
  • Salt and pepper
  • 1/4 teaspoon chopped fresh thyme leaves
  • 1/4 teaspoon finely chopped fresh rosemary
  • 1 cup grated Gruyère
  • 1 cup grated Pecorino

Directions

  1. Heat the oven to 400° F. Put the milk in a small heavy saucepan and peel and smash one of the garlic cloves. Add it to the milk and then heat the milk over low heat until it just starts to bubble at the edges. Remove from the heat, add the nutmeg and let steep while you continue with the recipe.
  2. Peel the second garlic clove, cut it in half and rub the cut side around the inside of a 6-cup baking dish no more than 2 inches deep. Rub 1 tablespoon of the oil all over the inside of the dish.
  3. Peel the squash, potatoes and parsnips and cut them into very thin slices (1/8-inch thick). If you have a mandoline, now's the time to use it.
  4. Layer the vegetables into the baking dish, alternating between squash, potato and parsnip, and fanning them into concentric, overlapping circles. Season generously with salt and pepper and sprinkle a third of the cheese and a third of the chopped herbs over the slices. Repeat twice, making the top layer as neat and tidy as you can.
  5. Remove the garlic clove from the hot milk and pour the milk evenly over the vegetables. Drizzle the remaining olive oil over the top of the gratin and bake for about 50 minutes, until the top is browned and bubbly and the vegetables yield easily when you poke them with a sharp knife. If the vegetables are tender but the top isn't as brown as you'd like, turn on the broiler for a couple of minutes -- watch it carefully so it doesn't burn! Let the gratin cool for at least 5 minutes before serving.

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Cheese|Potato|Vegetable|Thanksgiving|Fall|Christmas|Gluten-Free|Vegetarian|Entree

Reviews (70) Questions (1)

70 Comments

Footnotes November 11, 2017
I'm so excited to try this! I love playing with roots in new ways. Question... is the original recipe that Merrill mentions (potato gratin) the essentially the same save the roots?
 
gillianknitsalot September 30, 2017
So delicious, but mine separated as well. So, not pretty but very tasty.
 
judy November 5, 2016
I often have a problem with broken sauce is recipes like these. I wonder if a spoonful of flour thrown into the milk would work? Or perhaps make a slurry then add?
 
glammie December 31, 2015
I don't have an answer about the liquid, but I've found that if I cook a gratin at 324 (a nice slow oven) the cheese doesn't seize.
 
SallyF December 2, 2015
PS, I re-read and noted several comments re excessive liquid after baking. I stated that I did not have any extra juicy liquid in my casserole. I am now wondering if, by baking out ahead of time, the vegs may have soaked up any juices? I guess I'll never know!
 
SallyF December 2, 2015
I have been saving this recipe for a couple weeks, decided to "make/test run it" yesterday for husband and I. The slicing prep is a bit labor intensive, but the final result is OH SO WORTH IT! I actually made it late morning and we didn't eat it until dinner. After baking (mine was done in 45 min.), I covered the casserole with a lightly sprayed EVOO piece of foil, held it aside, and for dinner sliced pie shaped slices and reheated them (covered) in the microwave. OH SO GOOD!! The flavor is excellent! I wish the casserole was a little thicker (because I wanted more!) But the slices were pretty on the plates. I am testing further to see how the leftovers will freeze, then reheat. I had no problem with curdling or watery juice collecting from the vegs, even after sitting for several hours. The only change I made was to add 2 cups of milk because my bottle was a small 2 c. bottle so I decided to use it all. Don't deviate from the rest of the ingredients - the Gruyere and Pecorino impart a wonderful flavor to the 3 vegs. I wish slicing was easier, that took the longest. Make sure the squash has a long enough neck to keep slices solid and round. I was lucky enough to find a huge parsnip at the market. I will definitely make this again but next time will test by assembling all ahead of time, then bake out 45 min before dinner is ready. In that case, that little extra milk might help being added right before baking? Bottom line, EXCELLENT GRATIN!
 
John December 1, 2015
What a beautiful picture. It look so delicious this recipe I can't wait to make it.
 
Laura415 November 14, 2015
I will make this but I will use this method of making a gratin,<br />https://food52.com/recipes/32682-todd-coleman-s-potato-gratin<br />Essentially you cook your sliced root veggies in the milk mixture until they are tender but not done. Then layer in dish with cheese etc and bake until the cheese is melted. The starch from the potatoes comes out into the milk and the veggies are mostly cooked so no watery mess of curdled milk and separated cheese.
 
Emily November 14, 2015
Can the time/temp be adjusted? I want to pop it in alongside my turkey towards the end, which is cooking at 325.
 
GH November 10, 2015
I thought it wouldn't happen to me, but it did. A watery mess and curdled cheese. I substituted yellow beets for the potatoes, so maybe that eliminated some starch to thicken it. I used almond milk but aside from that I followed the recipe exactly. In the past I have always used cream and covered the gratin, uncovering it only to brown the top. I also thought it would thicken upon standing but no luck.
 
Danielle November 4, 2015
I made this the other night and unfortunately, didn't have great results. I'm wondering if you could give me some insight as to why, since I loved the flavors and would love to try to make it again. I guess my biggest concern was that all of the cheese seemed to slide down to the edges of the dish once I poured the milk over it. Then the cheese took on a curdled look instead of gooey and cheesy. I also felt like the potatoes released water while cooking, which added a bit too much liquid to my dish. Like I said before, the flavors were still there and wonderful - I've actually been eating the leftovers with my eggs every morning for breakfast! - I would just like to know where I went wrong. Thanks!
 
Kris L. November 8, 2015
I made this last night and had the same issues. Tastes great but wasn't pleased with the watery curdled mess. Ives read all the comments and not one person responded as to what went wrong or maybe it's supposed to look like that?????
 
Barbara November 17, 2015
Laura 414 wrote she cooks the veggies in the milk mixture until tender but not done then does the layering. She said the milk and cheese doesn't turn into a watery curdled mess. Just so you know you won't always get a response, just sayin
 
Danielle January 2, 2016
Thanks to all for the responses. I'm going to try this again with your tips!
 
Anne M. October 31, 2015
Just found this recipe. Looks fabulous. Can it be made ahead and reheated?
 
Luci Z. October 3, 2015
Oh my, I just made this and it is exquisite! I was determined to make it with what I had on hand, which was a butternut squash, potatoes and two cheeses- Asiago and horseradish-cheddar. So I went with that and threw in a little Parmesan as well. I also used skim milk with a little non-fat half and half rather than whole milk. And it came out perfectly delicious. A real keeper, this one! I can't stop eating it.
 
Wanderwoman October 2, 2015
Did anyone have any problems slicing the parsnips with the mandolin? They're so pointy I imagine the slices up to the middle part would be so tiny that at 1/8" thickness they'd disintegrate into the dish. Also, was it difficult to form those bitty slices into concentric circles?
 
Patricia December 28, 2014
Well, the recipe stated 'repeat twice' while adding the cheese, but as I had commented earlier on, I FORGOT the cheese and because it did not NEED to look pretty for that occasion, I threw caution to the wind and tossed all with the cheese ...made NOT a difference to the GREAT taste!!!
 
Author Comment
Merrill S. December 28, 2014
Love your laissez-faire approach (sounds exactly like something I would do), and glad it all worked out!
 
rpkc15 December 28, 2014
I am making this now and have a quibble with how the recipe is written. Step 4 says to layer the vegetables, so I did that, but then it says to put the cheese between the layers. So I had to un-layer and add the cheese. It does smell very good. Used the cuisinart to slice as my madeline was not really sharp enough for these roots!
 
Author Comment
Merrill S. December 28, 2014
As Patricia mentioned, the recipe does say to create one layer of vegetables, sprinkle with cheese and then repeat this process twice more (for a total of three layers of vegetables, with cheese in between each). Apologies if you were confused by the way it was written, and hope it turned out OK!
 
marynn December 26, 2014
Ok, late to the party, here! I made this for Christmas Dinner to keep company with a Roast Crown Pork Roast with Gorgonzola Sauce (credit: Epicurious and Serious Eats). All I'm saying is, why bother with the roast? Just hand me a spoon for this. Even veg-suspicious husband thought this was outstanding. Merrill, this is outstanding! I made it as directed (was tempted to up the herbs, but respected your expertise and did not) and swapped out the Russet for a white sweet potato. Might offset the cheese? >;) This is a signal dish! Thank you so very much.
 
Author Comment
Merrill S. December 28, 2014
So glad it was a success!
 
AK December 23, 2014
Somehow I picked up a container of fresh sage instead of thyme. Any thoughts on how that would work out in this dish?
 
Author Comment
Merrill S. December 23, 2014
I think it would be nice!
 
AK December 23, 2014
Thank you! I will give it a try, then.
 
Trish November 26, 2014
Thank you! Happy Thanksgiving, I appreciate it.
 
Trish November 26, 2014
Can someone please answer the question if this can be prepped with or without the liquid ahead of time. Say a day before. Pleas. Thank you
 
Terry A. November 26, 2014
Yes, assemble without the liquid ahead of time - a day ahead. The potatoes tend to discolor a bit when sitting, so toss them in the smallest amt. of olive oil before adding them to the dish to prevent discoloration. Add the liquid just before baking. Let us know how it turned out.
 
Author Comment
Merrill S. November 26, 2014
The potatoes and parsnips will discolor a little if you assemble it ahead without baking, but that may not matter to you. Don't forget to cover it tightly and refrigerate until you're ready to add the liquid!
 
robin L. December 17, 2014
any other make-ahead ideas/successful attempts? i'd like to make it a day ahead, either completely or as suggested here just up to the point of assembling then adding the liquid before baking the next day...