Italian Cheesy Chicken Burger

While the fries are baking, thinly slice the red onion. In a large frying pan, heat a drizzle of olive oil over a medium-high heat. Cook the onion, stirring, until softened, 5-6 minutes. Add the balsamic vinegar, the water and brown sugar and cook until dark and sticky, 4-5 minutes. Transfer to a bowl and cover to keep warm.

While the onion is cooking, place your hand flat on top of each chicken breast and slice through horizontally to make two thin steaks.

In a large bowl, combine the Italian herbs (see ingredients), the salt and a drizzle of olive oil. Add the chicken, then season with pepper and turn to coat.

Wash and dry the frying pan, then return to a medium-high heat. Cook the chicken until cooked through, 3-5 minutes each side (cook in batches if the pan is getting crowded). In the last 3 minutes of cook time, sprinkle the grated Parmesan cheese over the chicken and cover with a lid (or foil) to melt the cheese. Remove from the heat and set aside. Meanwhile, bake the burger buns directly on a wire oven rack until heated through, 3 minutes. Thinly slice the tomato.