Preheat the oven to 180°C. Take the lasagna al forno out of the fridge and let it sit at room temperature for 10-15 minutes. Cover it with foil and bake it in the oven for 20-25 minutes until it is heated through. Remove the foil and bake for an additional 5-10 minutes until the top is golden and bubbly. You may want to let it cool for a few minutes before serving.