Make the potato waffle batter

• Combine the mashed boiled potatoes with the egg, flour, spices and cheese in a large bowl.
• If the mixture feels too thick, add a splash of milk to loosen it up.

Cook the potato waffles

• Preheat the waffle maker and lightly grease it with oil.
• Spoon some of the potato mixture onto the waffle maker, spreading it evenly.
• Close the lid and cook until the waffles turn golden brown and crispy.
• Carefully remove them once done.

Caramelize the onions and mushrooms

• Sauté the onions in a large pan with butter, salt and sugar until softened.
• Add the mushrooms and cook until caramelized.

Cook the cheese patties

• Season the beef patties with salt, pepper and your favorite spices.
• Grill them until juicy and cooked to your liking.
• Add a slice of cheddar cheese on each patty.

Make the special sauce

• Mix the mayonnaise, ketchup, mustard, pickles, salt and pepper.

Assemble the burger

• Stack the sauce on the bottom waffle.
• Place the lettuce and tomato slice.
• Add the cheesy patty on top with the caramelized onions and mushrooms.
• Drizzle with special sauce and crown it with another waffle.