Preheat the oven to 375F. Lightly grease a casserole dish.
In a large skillet over medium-high heat, cook the potatoes water and olive oil. Season with salt and pepper.
1 lbs. russet potatoes, 1 teaspoon olive oil, ¼ cup water
Transfer the cooked potatoes to the prepared baking dish.
To the skillet, add the ground beef and onions, along with the seasonings.
1 lb. lean ground beef, ½ white onion, 2 teaspoons yellow mustard, ½ teaspoon garlic powder, ½ teaspoon onion powder, kosher salt and black pepper, 1 tablespoon Worcestershire sauce
Once cooked, add the beef mixture on top of the potatoes and stir to combine.
Top with cheese.
1 cup shredded cheddar cheese
Cover with aluminum foil and cook for 15 minutes to melt the cheese.
Mix up the big mac sauce.
¼ cup mayonnaise, ¼ cup ketchup, ¼ cup relish, 1 tablespoon dill pickle juice
When the casserole is done, drizzle the sauce on top and add the additional toppings.
1 large tomato, ¼ cup white onions, ¾ cup shredded iceberg lettuce, ¼ cup dill pickle chips