Yield: 8 servings.
1 (16-ounce) box elbow macaroni
1 stick salted butter
¼ cup all-purpose flour
2 cups half-and-half, warmed
1 cup 2% milk, warmed
8 ounces cream cheese, cut into small cubes
1 teaspoon salt
½ teaspoon dry mustard
½ teaspoon freshly ground black pepper
¼ teaspoon freshly grated nutmeg
2 large eggs, lightly beaten
2 cups shredded Monterey Jack cheese
2 cups shredded sharp Cheddar cheese, divided
Preheat oven to 350°. Prepare a deep, 9 x 13-inch casserole dish with 1 tablespoon softened butter.
In a stockpot, cook pasta per instructions until just tender. Drain pasta and return to the pot.
In a heavy saucepan, melt remaining butter over low heat. Add flour. Increase heat to medium and stir with a wooden spoon until roux is frothy. Gradually add half-and-half and milk, stirring constantly. Just before liquid begins to boil, reduce heat. Add cream cheese and simmer for 2 to 3 minutes or until cream cheese melts, stirring constantly. Stir in salt, mustard, pepper, and nutmeg. Remove from heat.
While stirring cheese sauce, gradually add beaten eggs, then Monterey Jack cheese and 1 cup of sharp Cheddar. Continue stirring until the cheeses melt.
Pour cheese sauce over cooked pasta and toss until well combined and pasta is covered with sauce. Pour into the prepared casserole dish and sprinkle the remaining sharp Cheddar over the top. Bake for 30 minutes or until bubbling and golden brown.