Mix the burger patties: In a bowl, combine the chicken mince, spring onion, red pepper, parsley, oregano, smoked paprika, salt and pepper. Mix well and shape into 4 patties with damp hands.
Cook and melt the cheese: Heat the olive oil in a non-stick pan over medium-high heat. Add the patties and cook for 5–6 minutes on each side, or until golden and cooked through. Flip them once only. Add a slice of cheese to each burger, reduce the heat, and cover with a lid to steam for 1–2 minutes until the cheese is melted.
Make the sauce: Stir together the mayo, sriracha, and lemon juice in a small bowl.
Prep the buns and salad: Slice and lightly toast the brioche buns. Wash the lettuce, slice the tomato, and slice the red onion into rings.
Build your burger: Spread the sriracha mayo on both top and bottom buns. Layer with lettuce, tomato slices, red onion, then the cheesy chicken burger. Cap with the top bun and serve warm.
