01 - Combine ground turkey, breadcrumbs, egg, minced shallot, garlic, Dijon mustard, salt, pepper, and parsley in a large bowl. Mix gently until just incorporated, being careful not to overwork the meat which can result in tough patties.
02 - Shape the mixture into 4 equal patties, making them slightly wider than your burger buns to account for shrinkage during cooking. Create a slight indentation in the center of each patty to prevent puffing.
03 - Heat olive oil in a large skillet or grill pan over medium heat. Place patties in the pan and cook for 5–6 minutes until a golden-brown crust forms on the bottom.
04 - Flip each patty and immediately top with a slice of Swiss cheese. Continue cooking for 4–5 minutes until the cheese is fully melted and the internal temperature reaches 165°F for safe consumption.
05 - Lightly toast the split burger buns until golden and crispy. Spread mayonnaise on the bottom halves if desired.
06 - Layer lettuce leaves and tomato slices on the toasted bottom bun. Place the cheesy turkey patty on top, arrange fresh avocado slices over the cheese, and finish with the top bun.
07 - Serve immediately while the cheese is still melted and the patties are hot. Pair with sweet potato fries, coleslaw, or a simple green salad.