Prep the Oven: Preheat your oven to 350°F (175°C) to ensure it is hot and ready for baking.

Brown the Meat: In a large oven-safe skillet, sauté the ground beef and chopped onion over medium-high heat on the stovetop. Cook the mixture until the beef is fully browned and the onions have softened, then carefully drain any excess fat from the pan.

Build the Base: Reduce the heat slightly and add the taco seasoning, canned green chilis, and cream cheese directly into the skillet. Stir continuously until the cream cheese is completely melted and smoothly combined into the savory meat mixture.

Layer the Crunch: Evenly distribute the corn chips over the top of the creamy beef base. Follow this by sprinkling an even layer of the shredded taco blend cheese over the chips.

Bake the Casserole: Transfer the skillet to the preheated oven and bake for 20 minutes, or until the cheese is beautifully melted and bubbling around the edges.

Add Fresh Toppings: Carefully remove the hot skillet from the oven and allow it to rest for a few minutes. Top the baked casserole evenly with the fresh shredded lettuce and chopped Roma tomatoes.

Garnish and Serve: Serve immediately straight from the skillet, garnishing individual portions with fresh salsa and dollops of sour cream as desired.