Cheesy Taco Pasta

Name: Cheesy Taco Pasta
Cuisine: American, TexMex
Ingredients: 1 pound ground beef or ground turkey; 1 small onion (chopped); 2 cloves garlic (minced); 1 packet (1 oz taco seasoning mix); 1 can (10 oz diced tomatoes with green chilies, undrained (such as Rotel)); 1 cup beef broth or chicken broth; 2 cups uncooked pasta (such as elbow macaroni or rotini); 1/2 cup milk; 2 cups shredded cheddar cheese; 1/2 cup shredded mozzarella cheese; 1/4 cup sour cream; Salt and black pepper (to taste); Fresh cilantro or green onions (chopped (optional, for garnish))