Green Chile Mac and Cheese Stew

Name: Green Chile Mac and Cheese Stew
Ingredients: 1 pound Mexican chorizo; 1 sweet onion (diced); 4 cups beef broth; 1 10 ounce diced tomatoes with green chiles (drained); 1 16 ounce chili beans (undrained); 2 teaspoons chili powder; 1/2 tablespoon dried red pepper flake (or more); 1/2 pound elbow macaroni; 1/2 cup green chile sauce (I made my own, but you can use jarred or canned, or leave it out); 8 ounces Mexican Velveeta cheese (cubed); Habanero Jack cheese (shredded and cilantro, chopped, for garnish (optional))