Loaded Taco Bake

In a large cast iron or high sided skillet, heat the oil over medium-high. Add the beef, onion, and garlic, cook, breaking up the beef with a spoon, until beef is no longer pink and golden, about 8 minutes. Drain fat and return to medium-high heat. Pour in crushed tomatoes, pinto beans, green chili, taco seasoning, and 3/4 cup water. Bring to a boil. Reduce heat and simmer, stirring occasionally, until slightly thickened, about 20 minutes. Spread a small amount of the beef mixture on the bottom of a 8-by-10 inch baking dish, then top with a layer of taco shells. Add a third of the meat mixture, 1/3 of the cheese, then repeat with another layer of taco shells, beef, and cheese. Top with the remaining layer of the taco shells and the remaining third of the meat mixture. Sprinkle top with taco shells broken in small pieces and the remaining cheese. Bake until cheese is melty and the casserole is warmed through, 20 to 25 minutes. Garnish with some of the avocado, cilantro, tomatoes, green onion, and chiles and serve with more on the side.