Slow-Cooker Chicken Breasts With Creamy Mustard-Leek Sauce

October  4, 2022
21 Ratings
Photo by Ty Mecham
  • Prep time 20 minutes
  • Cook time 2 hours 45 minutes
  • Serves 2 to 4 people
Author Notes

An editor at Food52 asked me to develop a recipe for chicken breasts prepared in a slow cooker. I was initially concerned that the lean meat would dry out. But this recipe produces tender, savory chicken that's also marinated overnight, which helps impart flavor. The mustard-leek sauce is rich and flavorful, with a nice tinge of acidity from the mustard. It's based on classic French preparations of rabbit in mustard sauce. —Josh Cohen

What You'll Need
  • For the Marinade
  • 1/3 cup mayonnaise
  • 2 tablespoons cider vinegar
  • 1/2 teaspoon salt, plus more for the slow cooker
  • 1 tablespoon fresh rosemary, finely minced
  • 1 tablespoon fresh sage, finely minced
  • 2 boneless, skinless chicken breasts
  • For the Slow Cooker
  • 1 shallot, finely minced
  • 1 leek, trimmed and cleaned, cut into thin half moons
  • 3/4 cup chicken stock
  • 1 tablespoon cornstarch
  • 1 tablespoon whole-grain mustard
  • 2 tablespoons dry white wine
  • 1/3 cup heavy cream
  • 12 ounces egg noodles
  • 3 tablespoons butter
  • 1 handful fresh chives, finely chopped
  1. To make the marinade, add all the marinade ingredients except the chicken to a mixing bowl. Stir to combine. Nestle the chicken in the marinade. Cover and store in the refrigerator overnight.
  2. Add the shallot and leek to the slow cooker, along with a pinch of salt. Add the chicken stock and cornstarch to the slow cooker, and stir to combine. Make sure the cornstarch is dissolved in the chicken stock with no lumps. Add the mustard, white wine, and heavy cream, stirring once more to combine everything.
  3. Add the marinated chicken to the slow cooker, discarding any excess marinade. If some marinade and herbs are clinging to the chicken when you add it to the slow cooker, that's fine. Set the slow cooker to low, and cook for 2 1/2 hours. When about 2 hours have passed, boil water in a large pot and cook the egg noodles according to the directions on the package. Toss the cooked egg noodles with butter and set aside.
  4. After 2 1/2 hours, check to see if the chicken is fully cooked. If it's less than 165°F at its thickest point, continue cooking. Check the chicken every 15 minutes until it's fully cooked.
  5. When the chicken is fully cooked, transfer it to a cutting board and slice it into medallions. Taste the sauce in the slow cooker. Add more salt as needed.
  6. To serve, arrange some chicken atop a portion of egg noodles. Top with sauce. Garnish with chives.

See what other Food52ers are saying.

  • Kathy Sabel
    Kathy Sabel
  • Rebekah Keegan Royston
    Rebekah Keegan Royston
  • Christine Gilpen
    Christine Gilpen
  • Josh Cohen
    Josh Cohen

19 Reviews

Linda D. June 28, 2022
Thank you, Josh for this fabulous dish! I used a pound of boneless chicken thighs and the cooking time stayed the same. The next time, I will use 2 pounds of chicken thighs. There was plenty of sauce and I want left overs!
BaliThai May 17, 2022
For those that have made this with boneless chicken thighs, did it change the cooking time at all? Thighs are more forgiving, but they are smaller too, so just wondering what other's experiences have been! Thank you!
Janice H. May 17, 2022
See comment from Rebekah K. below. Given it’s a slow cooker recipe, I don’t think there would be much, if any, time difference.
lisagilbert March 1, 2021
I made this with a few tweaks: subbed tarragon for the rosemary & sage, used cognac instead of white wine, and added a can of drained, chopped artichokes to the mix. 2lbs of chicken cut into smaller pieces meant that there was no excess marinade. Recommend the sharpest mustard you've got; I also put in a bit of smooth dijon to try to amp up the mustard flavor (which was a little buried under all that mayo). Was careful not to overcook - it's really not clear why this is a slow cooker recipe instead of just an oven one, tbh. But, it ended up tasty!
Kathy S. December 30, 2020
I'm glad I set my slow cooker to "high" instead of "low" temp. I used one bone-in chicken breast and after 2 hours it wasn't close to being done. I broiled the breast to char the skin, add flavor and finish the cooking. The sauce was thin so I added sour cream and more chopped fresh rosemary. Next time I will saute the leeks and shallot and add mushrooms. It's worth giving it another try.
Beth L. September 4, 2020
It was really good, but next time I will saute the leeks and shallot first. It tasted a little too raw onion-y for my taste. My leek was pretty big. Might add a few mushrooms too. The sauce was a little thin, but worked well over noodles.
Rebekah K. August 21, 2020
I made this last year for the first time. It was the first fall in our new house and I wanted to make something new and different and use my slow cooker. I had to find more good slow cooker recipes!!! See I homeschool five of my children and then there is this small person who hasn't taken a nap, bless her heart, since that day when she was two and STARTED sleeping through the night! Plus there is the fact that I start my "clean house routine" at 3pm... but if ANYTHING else is going on that day I end up with dinner at 7/8 at night! This sets up everyone for hangry outbursts or breakdowns. That is where the SLoW CooKeR comes in and saves the day! I'm so glad I tried this I'm not lying I wake up some mornings knowing I'm going to make this. I could drink the gravy. It's amaaaaazzzzing!!! You can use chicken thighs as well! I imagine this would be equally great for pork chops/loin. I'm making this again tomorrow and marinading my chicken today! <3 Thank you for this recipe Josh!
Josh C. August 22, 2020
Hi Rebekah, thanks for the great feedback - and I agree about the chicken thighs (in fact I think this recipe is better with chicken thighs rather than breasts)
Lesterj2 October 7, 2019
Pros: Sauce was fabulous. We didn't find it too thin given that it was served over noodles, and my family all agreed they'd happily eat the sauce with anything - it was that good. Recipe was easy to pull together and the crock pot preparation minimized clean up.
Cons: I made the mistake of NOT checking the chicken until nearly 2.5 hours and by the time I did it was overcooked and pretty dry. My breasts were over 1/2 pound each but I suspect would have been done a good half hour earlier. My fault. Also the dish is very beige, even with the addition of the chives and the herbs in the sauce.
Next time I will probably try some or all of: adding some chopped spinach/kale/etc to the sauce; browning the chicken before adding to the sauce ingredients; making it on the stove top or in the oven.
But with some tweaks, it's definitely a keeper if for the sauce alone!
jacci F. July 7, 2019
So just made this tonight for dinner. The only thing I did differently was use boneless, skinless thighs because that is what I had. The flavor was great! Here are my issues: For me, the entire point of a crockpot dinner is to fix it in the morning and come home to a fragrant cooked meal, with minimal additional work to get it to the table. I don't find any reason to use a crockpot other than that., it is not a superior cooking method. At 2 1/2 hours this does not only not meet that criteria - it means, if I start to cook it when I get home from work - I am at least 3 hours in until dinner- that doesn't work. My second observation is that, First, why on earth would I cook and butter the noodles 1/2 an hour before the chicken was done? Cold, congeled noodles add nothing to a dish! So I timed that entirely differently so that the warm buttered noodles were (supposedly) done at the same time. My last issue with this dish is that the sauce was so watery it was not usable to dress the dish as is. I dissolved more cornstarch and water and cooked it to thicken it to a gravy consistency. I have about a cup and a half of sauce (delicious) left. I am thinking it would be delicious on a seared pork chop one night and that is what i am going to use the leftovers for. I would love to hear everyone else's thoughts on my observations.
Phil P. June 30, 2019
When I tried this, the sauce seemed a little thin and might benefit from thickening, which surprised me since it has a tablespoon of cornstarch. Has anyone else experienced this? Thoughts?
Josh C. July 1, 2019
If the sauce is a little too thin for your liking, you can always experiment with adding an extra teaspoon of cornstarch
NYA June 29, 2019
I just made this and was so excited to eat it, but the milk curdled/clumped/broke...did this happen to anyone else? Is it OK to eat it? How do I prevent this from happening next time??
Phil P. June 30, 2019
Did you use milk or cream? Did you check the date? With cornstarch acting as an emulsifier, you shouldn't get any curdling even if you used milk AND the wine had gone to vinegar.
Josh C. July 1, 2019
the recipe calls for 1/3 cup of heavy cream - there is no milk in this recipe
Christine G. June 12, 2019
I made this last night and it was fantastic. My 8 yr old twins loved it. I did embellish, I caramelized the Leeks and Shallots in olive oil before adding them to the crockpot, I also added fresh thyme, more white wine and garlic. When the chicken was finished I did have to adjust for salt and pepper, I also added just a pinch of sugar. A nice french dinner on a summer night. DELICEUX!!
Janice H. June 9, 2019
This looks really tasty. However, chicken breasts vary in size so much. How many ounces of chicken breast is this? Thanks!
Josh C. June 10, 2019
Hi Janice, one raw chicken breast should weigh approximately 8 ounces. So, this recipes uses about 1 pound total of chicken breast meat. That being said, if you're over or under by a few ounces, it shouldn't make a real difference.
Janice H. June 30, 2019
Thanks! I think it would be helpful to state ounces, because chicken parts vary so much in size.