01 -
Preheat oven to 350°F (175°C).
02 -
In a 5 to 6 quart saucepan over medium-high heat, cook ground beef and chopped onion, stirring frequently until beef is cooked through and no longer pink, about 5 to 6 minutes. Drain excess fat.
03 -
Add 1 cup water and taco seasoning packets to the beef mixture, stirring continuously for 3 to 4 minutes.
04 -
Stir in drained diced tomatoes with green chilies, black beans, and half of the jarred salsa. Heat until mixture begins to simmer, then remove from heat.
05 -
Spread the remaining half of the salsa evenly in the bottom of a 9x13 inch baking dish.
06 -
Place 6 corn tortillas over the salsa layer. Spread one-third of the meat mixture evenly over the tortillas, then sprinkle with 2 cups of shredded Colby Jack cheese.
07 -
Repeat the layering with 6 tortillas, one-third of the meat mixture, and 2 cups of shredded cheese.
08 -
Add the final 6 tortillas, remaining meat mixture, and 2 cups of shredded cheese. Cover loosely with aluminum foil.
09 -
Bake covered for 35 minutes, then uncover and bake an additional 5 minutes to brown the cheese.
10 -
Allow to rest for 10 to 15 minutes to let tortillas absorb sauce. Cut into 12 equal pieces and garnish with diced Roma tomatoes, sliced green onions, and sour cream if desired. Serve hot.