1 3 to 4 pound whole chicken
5 cups of water
1 celery stick, roughly chopped
1 carrot rought chopped
1 onion, quartered with 1 whole clove inserted in one section
2 smashed garlic cloves
2 sprig of thyme
Salt and pepper to taste
Sauce and Pasta:
1/2 stick unsalted butter
1/4 cup flour
1 1/2 cups whole milk
1/2 cup sour cream
salt and pepper to taste
dash of cayenne pepper
1/2 lb Gruyere cheese, coarsely grated (3 cups), divided
2/3 cup finely grated Parmesan cheese, divided
1/2 pound penne pasta
3 cups dried bread crumbs
Butter a 9 X 13 casserole. Place chicken in large stock pot. Add water and vegetables and seasonings. Bring put to a boil and reduce heat to a simmer. Cook Chicken until it is tender. Remove chicken from stock and set aside to cool. Strain stock through a fine mesh strainer.
Make cheese sauce: Heat butter in a heavy pot over moderate heat until foam subside, then whisk in flour. Cook for 1 minute while whisking. Add 2 cups of the chicken stock (freeze the rest for future use) in a slow stream while whisking, then bring to a boil. Reduce heat and simmer, whisking occasionally, until sauce is slightly thickened, about 10 minutes. Remove from heat and stir in sour cream, milk, salt, pepper, cayenne, 1 cup Gruyere and 1/3 cup Parmesan.
Cook pasta in boiling salted water until not quite al dente, 8 to 10 minutes. Drain. Return pasta to pot, then add chicken and sauce, tossing to coat. Turn mixture into buttered casserole.
Toss bread crumbs with remaining 1 cup Gruyere and 1/3 cup Parmesan, then sprinkle evenly over pasta mixture. Bake casserole in a 400 degree oven until crumbs are browned and sauce is bubbling, 20 to 30 minutes.