
Sauce
To Assemble the Sandwich
Start by shaping the ground beef with the help of a Coca Cola can.
Then, in the center, add the barbecue sauce, the mustard, the ketchup, the red onion chopped into small cubes and mix everything together very well until fully combined.
Add the grated Parmesan cheese and the slices of mozzarella cheese.
Transfer it to an Air Fryer, set it to 180 ° C (350 ° F) and let it fry for 10 minutes.
In a large skillet over medium to low heat, add the unsalted butter and stir until it has completely melted.
Add the hamburger bun sliced in half and toast it until golden brown.
In a small bowl, add the mayonnaise, the pickled mustard seeds, the barbecue sauce, a pinch of black pepper and mix everything together very well until combined.
To assemble the sandwich, add 1 tablespoon of the sauce we prepared to the bottom of the bun and spread it evenly.
Add some red onion to taste, sliced pickled cucumbers to taste, the burger we prepared, + 1 tablespoon of the sauce and close the sandwich.
Serve.