Preheat oven: Set to 375 °F.
Cook beef: In a skillet, heat oil, then add onion and garlic. Sauté until fragrant. Add ground beef and cook until browned. Drain excess fat.
Season: Stir in chili powder, paprika, cumin, oregano, salt, and pepper. Mix well.
Make the sauce: In a small bowl, whisk enchilada sauce, tomato paste, broth, vinegar, and xanthan gum (if using). Pour over beef and simmer 5 minutes.
Assemble casserole: In a greased baking dish (ca 20x30 cm), spread half the beef, top with half the cheese, then repeat the layers.
Bake: Place uncovered in the oven for 15–20 minutes, until cheese is melted and bubbly.
Finish: Garnish with jalapeños, fresh herbs, and serve with sour cream or avocado.