The Best Macaroni and Cheese

1/4 cup butter
1/4 cup flour
2 cups warmed whole milk
1 tsp freshly ground black pepper
1/2 tsp salt
1/2 cup heavy whipping cream
12 oz medium or sharp grated Cheddar cheese
2 T. leeks, finely minced
8 oz cooked elbow macaroni, al dente
1 tsp butter

Saute leeks in tsp of butter until soft. Set aside.

Melt the remaining butter, add flour, and cook for 5 minutes over very low heat, stirring often. Do not let the flour brown. Remove from heat, and stir in the milk gradually, with a whisk or fork, to prevent lumps. Cook this for another five minutes. Add salt, pepper, cooked leeks, and cream. Melt three-quarters of the cheese into the sauce.

Mix sauce and cooked macaroni, and pour into a greased 9 x 9 in. pan. Top with remaining cheese. Bake at 350-375 until the top and edges are slightly brown, 40 minutes or longer. Remove from oven, and let stand for 5 to 10 minutes before serving.