Search results for: leveling it with a spatula. Bake in a preheated oven at 180°C/360°F for about 20-25 minutes. Take your zucchini omelet out of the oven and stuff it with the slices of ham and the cheese cut into slices. Roll up the omelet with the help of parchment paper and bake for another 10 minutes at 180°C/360°F just enough time to melt the cheese. Cut into slices and serve.