Smash Burgers with Caramelised Onions, Comte Cheese and Toasted Brioche Bun - Bryant and May Matches

Ingredients

• 500g wagyu beef mince or 20% fat beef mince
• ½ tsp cracked black pepper
• 1 tsp salt
• 1 onion, peeled and finely sliced
• 2 tbsp American mustard
• 4 tbsp mayonnaise
• 1 tbsp ketchup
• 1 tbsp onion, diced
• 1 tbsp gherkin, diced
• 1 tbsp pickle gherkin juice
• Pinch of dried dill
• 4 slices of comte cheese or traditional burger cheese
• 4 slices of beef tomato, lightly season with salt
• 4 slices of raw red onion, lightly season with salt
• 4 small handfuls of shredded iceberg lettuce
• 4 brioche buns cut in half
• 12 fried onion rings
• 4 pickled gherkins or chillies