Preheat the oven to 220C/425F. Put half the oil in the bottom of a lasagne pan and tilt it around so it coats the bottom. Add potatoes, peppers, garlic, and onion more or less evenly, potatoes first. Add seasoning. Drizzle the other half the oil over the top. Cover with foil and bake for ~20 minutes. Uncover and add cheese. Bake ten more minutes.