1 tablespoon unsalted butter
1/4 cup minced yellow onion
1 1/2 tablespoons all-purpose flour
1 1/4 cups low-fat (2%) milk
1/4 teaspoon ground nutmeg
1/2 teaspoon salt
1/4 teaspoon ground black pepper
2 ounces reduced-fat Jarlsberg cheese
2 ounces reduced-fat cheddar cheese
8 ounces dried elbow macaroni, cooked until al dente and drained
2 ounces sharp yellow cheddar cheese, shredded
In a heavy saucepan over medium heat, melt butter and saute onion until just soft, about 2-3 minutes. Add flour and combine thoroughly. Continue cooking, stirring occasionally, another 5 minutes, being careful not to let the mixture brown.
Slowly add the milk to the flour mixture, whisking continuously (mixture will be extremely thick at the beginning and will thin out as milk is added). Continue whisking until smooth and flour is incorporated. Add nutmeg, salt and pepper and continue to cook, whisking occasionally, until sauce thickens, about 5 minutes.
Add Jarlsberg and cheddar to the sauce mixture and whisk until melted and smooth. Remove from heat. Add cooked pasta to the cheese sauce and stir until combined. Preheat oven to 350* F. Lightly oil an 8-by-8-inch baking dish and add the pasta mixture. Top with shredded sharp yellow cheddar and bake until warmed through and cheese is melted, about 15 minutes.