Set oven temperature to 350°F.

After removing excess fat, cut the chicken thighs into 1-inch pieces. Add kosher salt and freshly ground black pepper to taste. Heat the two tablespoons of olive oil in a big pot with a thick bottom or a cast-iron Dutch oven over medium-high heat. Add the chicken and cook, in batches if necessary, for approximately 10 minutes, or until browned. Move the chicken over to a bowl.

After removing any remaining crispy pieces from the saucepan, drizzle in the remaining tablespoon of olive oil. Cook the leek for approximately five minutes, or until it softens, after adding the carrots and garlic. For the flour to lose its raw flavor, add it and simmer for two minutes. After the vinegar has cooked down and thickened for approximately three minutes, add it to the saucepan and stir, scraping up any browned pieces from the bottom. When it comes to a boil, add the chicken broth. Readd the chicken to the saucepan and place a lid on it. Place the saucepan in the oven and let it cook for half an hour.

As you wait, boil a big pot of water and cook the noodles in salted water, following the instructions on the package. After draining, replenish in the pot. Toss in 2 tablespoons of butter and season with freshly ground black pepper and kosher salt. Place aside, wrap, and refrigerate.

After taking the stew out of the oven, add the remaining butter and stir until it melts. Garnish with parsley, add extra salt or pepper to taste, and serve over the buttered noodles.