Preheat oven to 400°F. Grease a 9x13-inch pan and set aside.
In a large skillet over medium-high heat, cook ground beef and butter, crumbling the beef as it cooks. Drain excess grease.
Add Thousand Island dressing, mayonnaise, diced onion, diced dill pickle, onion powder, garlic powder, salt, and pepper to the skillet. Stir to combine well.
Pour beef mixture into prepared baking dish. Sprinkle cheddar and Colby Jack cheese over the beef, then top with a single layer of frozen tater tots.
Bake for 40-45 minutes, or until the tater tots are golden brown.
Remove from oven and top with shredded iceberg lettuce and a drizzle of Thousand Island dressing.
Serve warm and enjoy!
Notes
This crowd-pleaser brings all the flavors of a Big Mac in cozy casserole form. You can add sesame seeds on top after baking for a fun 'bun' touch!