First, you'll want to preheat your oven to 350 degrees Fahrenheit.
Add the onion and ground beef into a skillet that's on medium-high. You'll want to ensure your onions are fully chopped to the size you desire. Allow the meat to brown and the onions to come to a more translucent color in nature before moving on to the next step.
Add additional ingredients, including the taco seasoning (or your own homemade mixture), green chilis, and cream cheese to the skillet. Do this only once the beef has been completely browned.
Sauté the ingredients until the cream cheese is fully combined. Mix all toppings you've added into the beef mixture.
Add your preferred brand and type of corn chips on top of the mixture.
Add your shredded cheese to top the corn chips.
Place the oven-friendly skillet in your oven for 20 minutes.
Once the cheese is melted, remove the skillet from the oven. You can then top the walking casserole with remaining ingredients, such as tomato, lettuce, more cream cheese, chilis, and jalapenos.
Garnish with items such as sour cream and salsa, to taste.