Step 1

Preheat oven to 375°F.

Step 2

In a saucepan, heat milk until it is scalding (i.e. just before boiling). Keep on low heat.

Step 3

In a large pot, bring salted water to a boil. Add in olive oil. When ready, add in pasta. Cook until pasta is almost al dente. (The pasta will continue to cook in the oven.)

Step 4

Meanwhile, in a second large pot, melt 1 stick (8 Tbsp) of butter. Whisk in flour and cook over low heat until it forms a thick paste (about 2 minutes).

Step 5

While whisking, add the hot milk to the pot and cook until sauce is thick and creamy (about 5 minutes).

Step 6

Off heat, add in cheeses, salt, pepper, and nutmeg. Stir, and keep warm on low heat.

Step 7

Add in the cooked pasta, and stir. Pour mixture into a large baking dish.

Step 8

Melt the remaining ¼ stick (2 Tbsp) of butter, and mix it into the breadcrumbs. Sprinkle on top of pasta and cheese mixture.

Step 9

Bake until sauce is bubbly and the top of the pasta is browned (about 30 to 35 minutes).

Step 10

Serve hot, or allow to cool completely and refrigerate.