For the topping add the butter, oil, thyme, onion, chili's, salt and pepper to a pan over medium heat. Cook until onions are tender and thyme is fragrant 6-8 mins. Transfer to a plate and wipe pan for reuse.

For the patty whisk the Worcestershire, salt, pepper, and garlic in a small bowl. Break up the chuck in a separate large bowl. Gently combine the Worcestershire and ground chuck. Form the chuck into a bowl.

Heat the pan over medium high heat. Place the ball of ground chuck between sheets of parchment or plastic wrap. Flatten the ball to a size a little larger than the flat breads with a rolling pin. Place the flattened patty in a pan and cook 3 mins. Flip and cook other side 3 mins.

Adjust the oven rack to the center of the oven and heat to 350. Place one flat bread on a sheet of aluminium foil. Evenly layer the cheese on top and sprinkle with bacon. Place the patty on top and evenly spread the onion mix on top. Place the mozzarella on top. Place the second flat bread on top and tightly wrap the sandwich and bake 5 mins. Flip and bake another 5 mins.

Remove the sandwich and let rest 5 mins. Open foil and cut into wedges and serve.