In a large pot, cook the macaroni according to the pasta package directions. Drain and set aside.

In a large skillet, brown the ground beef with the chopped onion and crushed garlic and drain excess fat. Return the ground beef and onion mixture to the skillet, and add the tomato sauce, diced tomatoes, and milk. Stir in the cilantro, cayenne, and ground cumin, and simmer about 10 minutes, allowing the sauce to form and the flavors to mingle. Add the cooked elbow macaroni to the sauce and mix to combine. Sprinkle the cheese over the top of the mixture while still warm in the skillet, and allow the cheese to melt.