Make the burger sauce

• Combine the ketchup, mayonnaise, mustard, pickle juice and chopped pickles in a bowl.
• Mix well and set aside.

Caramelize the onions

• Cook the sliced onion in a pan over low heat until softened.
• Add the Worcestershire sauce and balsamic vinegar and cook until sticky.

Prepare the croissant glaze

• Mix the melted butter with the minced garlic, parsley and smoked paprika.

Season and smash the patties

• Season the beef patties with the black pepper, salt and all purpose seasoning.
• Smash the patties flat in a hot pan and cook until browned and cooked through, then flip.

Toast the croissants

• Brush the cut croissants with the garlic butter glaze.
• Toast them in the pan cut side down until golden.

Assemble the burger

• Spread the sauce on the croissant halves.
• Layer the patty, caramelized onions and more sauce, then close the croissant.