Peel the skin from the squash and cut it into ½ inch thick French fry shapes. Next, using a knife or mandolin cut thin slices of onion and set aside. In a mixing bowl, toss the cut squash with olive, salt and pepper. Spread out the seasoned squash on the All-Clad roasting sheet and dollop the butter throughout. Scatter the sliced onions on top of the squash and do the same with the sprigs of thyme. Bake the squash for roughly 20-25 minutes or until cooked through. If a crispier fry is preferred, leave the squash in the oven longer. Plate the cooked squash and onions and top with grated parmesan cheese.