For picky eaters, you can keep this casserole very plain and let the toppings do the talking—serve it with small bowls of shredded lettuce, diced tomatoes, sour cream, salsa, and even a little ranch dressing so kids can customize their plates. If your family likes things milder, choose a mild taco seasoning and a mild cheese; for more heat, use a spicy taco seasoning or add a handful of pepper jack cheese to the mix. You can also stretch the recipe for a bigger crowd by stirring in 1 cup of canned black beans (drained and rinsed) or a small can of corn to the cooked beef before layering, though that will technically add more than four ingredients. For a slightly lighter version, use ground turkey instead of beef and bake with a reduced-fat cheese. If someone in your house doesn’t like too much crunch, leave off the top layer of chips and just use them on the bottom, then serve extra chips on the side for dipping into the cheesy beef. And if you need this to be make-ahead friendly, you can cook and season the beef earlier in the day, then assemble and bake right before dinner so it comes to the table hot and bubbly.
