• Start by preheating your oven to 350°F. Grease a 2-quart casserole dish with butter or nonstick spray.

For the Beef Layer:

• In a large skillet over medium heat, brown the ground beef along with the diced onion, stirring occasionally. Once browned, drain any excess fat.
• Stir in the ketchup, yellow mustard, dill pickle relish, and ½ teaspoon of salt to the beef mixture. Combine well and spread this mixture evenly into the prepared casserole dish.

For the Cheese Sauce:

• In a separate saucepan, melt the butter over medium heat. Whisk in the flour until smooth and allow it to cook until it begins to turn golden.
• Gradually pour in the milk, whisking continuously, and stir until the mixture thickens and bubbles, which takes about 5 minutes. Season with ¼ teaspoon salt and black pepper.
• Remove from the heat and incorporate 1.5 cups of the cheddar cheese until it melts and creates a smooth sauce. Pour this cheese sauce over the ground beef layer in the casserole.

For Tater Tots Topping:

• Place the tater tots in a single layer on top of the cheese sauce, reserving some for later if needed.
• Bake in the preheated oven for 35 minutes. Then, remove from the oven and sprinkle the remaining cheese on top. Return to the oven to bake for an additional 5 minutes or until the cheese is bubbly and melted.
• Garnish with fresh Italian parsley if desired, and serve. This dish pairs wonderfully with a side salad for a complete meal.