Gnocchetti Sardi With Caramelized Onions, 3 Cheeses & Herby Breadcrumbs

Directions

1. Make the pasta dough:
   
   Make a batch of durum wheat flour and water pasta dough according to the well method (see my master pasta dough tutorial that teaches you how).
   
   Alternatively, add the flour to the bowl of a food processor with the steel blade attachment. With the machine running, stream in the water until beads of dough start to form, then pulse the mixture until a coarse couscous-like texture emerges. Transfer the dough to a flat, ideally wooden surface and knead for about 5 to 10 minutes until smooth and firm.
   
   Wrap the dough tightly in plastic and allow it to rest at room temperature for 15 minutes.
2. Make the pasta:
   
   Dust a baking sheet with a layer of semolina flour or cornmeal and keep it nearby. Grab a gnocchi board if you have one, or your textured kitchen tool of choice (see author notes). Alternatively, you can skip the tools altogether and make smooth pieces, which are known as cavatelli.
   
   On a wooden surface, cut off a small sliver of the dough with a bench scraper or sharp knife. Immediately re-wrap the remaining dough in the plastic wrap to avoid drying out. Roll the piece of dough into a rope, about 1/2-inch thick. Cut the rope into roughly 1/2-inch pieces. They should look like small gnocchi pillows.
   
   If the dough is sliding around on the board, coat the surface in a very small amount of water to get the friction you need. If it’s sticking to the board, dust the dough and your fingers in a little flour to get it moving.
   
   Place a piece of dough at one end of the gnocchi board or whatever tool you’re using. Press down slightly with the side and pad of your thumb, then firmly push the dough forward until it curls over on itself and becomes hollow. (To make smooth cavatelli, simply place the piece of dough directly on the wooden surface and push it forward with your thumb in the same way so it looks a bit like a seashell.) It’ll take a few tries to get the motion down, but don’t be shy with the pressure—you want them to be as hollow as possible to grab that sauce!
   
   Place each finished piece on the sheet tray and repeat the process with the remaining dough. Remember that if you’re not satisfied with a particular piece, you can scrunch it up and try again and it’ll taste delicious just the same!
   
   Storage notes: This pasta can be cooked right away or left to dry at room temperature for up to 4 to 5 hours. For long-term storage, freeze the pasta on the baking sheet until solid, about 30 minutes, then dust off any excess semolina flour from the bottoms and transfer to a freezer-safe bag or container. The pasta will keep best for a couple of weeks and up to about a month, and should be cooked straight from frozen.
3. Start the onions:
   
   Halve the onions through the root end and remove the skins. Using the tip of your knife, cut a V-shaped notch around the root to remove it.
   
   Place each half on your cutting board with the root end facing you, then slice the onion lengthwise into about 1/4-inch pieces (your knife should run through the root halfway through).
   
   Over medium-high heat, melt the butter in a large heavy-bottom saucepan or dutch oven. Add the onion slices and stir to make sure everything is coated in butter.
   
   Cook, stirring frequently, until the onions are softened and translucent, about 15 minutes. If they start to brown, lower the heat.
   
   Once the onions have softened, add a generous pinch of salt and stir to combine. The salt will help pull out the remaining moisture.
   
   Reduce the heat to medium-low and continue cooking the onions, stirring every few minutes, until they turn soft and golden. This can take up to an hour or more, depending on how hot your stove top is. In the meantime, toast the breadcrumbs.
4. Toast the breadcrumbs:
   
   Finely chop the thyme and rosemary leaves. You should have a couple of teaspoons in total, but I encourage you to add more if you prefer!
   
   In a large non-stick skillet, heat the olive oil over medium-high. Add the panko breadcrumbs and a generous pinch of salt, and stir until they’re completely coated.
   
   Cook, stirring occasionally, until they begin to brown, about 3 minutes. Once they start to turn golden, stir constantly until they’re evenly toasted and deeply golden, about 2 to 4 minutes more (if they start to darken too quickly, turn down the heat).
   
   Remove from the heat and stir in the herbs. Taste for seasoning and add a pinch more salt, if needed. Transfer to a bowl and set aside. (Note: Toasted breadcrumbs can be stored in an air-tight container at room temperature for several days, or in the freezer for a few months.)
5. Finish the onions:
   
   Once the onions start to stick to the bottom of the pan and become deeper in color, reduce the heat to low and stir them more frequently to prevent burning. If needed, deglaze the pan with a bit of water and scrape up any especially browned bits.
   
   Continue to cook, stir, and scrape until the onions are jammy and a rich, deep brown. The whole process can take up to 2 hours, so there’s plenty of time to prepare the ingredients for the sauce while you wait!
   
   When the onions are done, increase the heat to medium and deglaze the pan with the sherry vinegar. Cook, stirring frequently, 2 to 3 minutes until the sharpness has dissipated. Season to taste with salt and pepper, remove the onions from the pan, and set aside. (Note: caramelized onions can be made in advance and stored in an air-tight container in the refrigerator for several days.)
6. Make the sauce:
   
   Bring a large pot of water to a boil while you make the sauce.
   
   In the same saucepan or dutch oven that you used for the onions, melt the butter over medium-high heat. Follow with the flour and whisk to combine into a paste, or roux, scraping up any additional brown bits from the bottom of the pan. Continue whisking and cook for about a minute to remove the taste of the raw flour, and until the mixture smells nutty.
   
   Add the milk in a thin, steady stream, or a couple of tablespoons at a time, and whisk vigorously to combine. The mixture will get very thick at first, but will thin out significantly once all the milk is added.
   
   Continue to cook, stirring constantly, until the sauce begins to bubble, then reduce the heat to low and stir until it thickens and coats the back of a spoon, about a minute or two.
   
   Over very low heat, add the grated cheeses in 3 or 4 increments. After each bit of cheese is added, whisk thoroughly and, before it melts completely, add the next batch, then the next. Remove from the heat and stir in the caramelized onions.
7. Finish the dish:
   
   Add a generous amount of salt to a pot of boiling water and allow it to dissolve for a few seconds. Follow with the gnocchetti, making sure to shake off any excess coarse flour before dropping the pasta into the water.
   
   While the pasta cooks, which takes 3 to 5 minutes, reheat the sauce over medium-low and stir frequently. Add a small ladle of pasta water to the pan and stir until smooth and saucy.
   
   Taste the pasta for doneness. When it’s cooked to your liking (it should have a nice bite and slightly chewy texture), transfer it directly to the pot of sauce with a slotted spoon. Toss to coat and season to taste with salt and pepper. If the sauce continues to thicken, add a little more pasta water to thin it out. Remove from the heat and serve immediately, topped with plenty of breadcrumbs and more fresh herbs, if desired.