In a large bowl, add minced beef, onions, tomato paste, mustard sauce, salt, black pepper, garlic powder, paprika powder, parsley, and eggs. Gently mix everything using your hands (do not overmix, or the patties may become tough).
Wet your hands and shape the mixture into 8 patties, about ½ inch thick.
Use your thumb or tablespoon to make an indentation in the center of each patty (this prevents puffing during cooking).
Cover the patties with cling film and refrigerate for about 20 minutes, or until firm.
While patties chill, make the sauce by mixing mayonnaise, ketchup, mustard sauce, and chopped iceberg in a bowl. Set aside.
Heat a non-stick pan, add clarified butter, and cook the patties until browned and cooked through, turning occasionally (do not press the patties with a spatula, or they will lose their juices).
About 1 minute before the patties are done, place a cheese slice on each patty and cook until it starts to melt.
Let the patties rest for a few minutes after cooking to retain their juices.
Meanwhile, lightly toast the cut sides of the buns in the same pan to absorb extra flavor.
To assemble: spread the sauce on the bottom bun, layer with lettuce, a patty, tomato, and onion slices, then more sauce if desired. Cover with the top bun.
Serve with fries, onion rings, a bowl of salad, and a drink. Enjoy! And remember “COOKING IS EASY!”