Tex-Mex Macaroni and Cheese

1 pound ground pork sausage
1 small onion, chopped
3 tablespoons all-purpose flour
1/2 teaspoon ground cumin
2 cups milk
1 (16 ounce) loaf Mexican pasteurized cheese
1 (4 1/2 ounce) can chopped green chiles, drained
16 ounces macaroni, cooked
8 ounces shredded Southwestern cheese blend

Cook sausage and onion in a large nonstick skillet over medium-high heat until sausage crumbles and is no longer pink; drain.

Add flour, cumin and milk, stirring constantly, until thickened. Add Mexican cheese and chiles, stirring until cheese is melted. Add macaroni. Spoon mixture into a lightly greased 9 x 13-inch baking dish. Bake at 350 degrees F for 25 minutes. Sprinkle with shredded cheese blend, and serve with salsa.