Combine ground chicken, panko breadcrumbs, egg, grated Parmesan, chopped green onions, minced garlic, dried sage, salt, and pepper in a large bowl. Gently mix everything together with your hands until just incorporated.

Form four equal-sized patties, about 1.5cm thick, making them slightly larger than your buns.

Cook the patties in a skillet with heated olive oil over medium-high heat for about 2 minutes per side until deeply golden brown and cooked through.

Melt cheese by topping each patty with a slice in the last minute of cooking and covering the pan briefly.

Assemble your burgers by toasting buns, mashing avocado onto the bottom halves, and topping with the cheesy chicken patties, fresh rocket, and sliced tomatoes.