Courgette gratin with tomato and marjoram

Clean courgettes and slice thinly.
Put half the oil and all the garlic in a heavy-based saucepan over heat. When garlic begins to colour, add courgettes and sauté until tender, stirring occasionally. Remove from heat.
Place the onions and remaining oil in a small saucepan, turn the heat to medium and cook until onions are translucent, add tomatoes, juice and marjoram.
Turn tomatoes over once or twice to coat well and cook at a steady but gentle simmer until oil floats free of the tomatoes.
Remove from heat, and swirl in the parsley, salt and pepper.
Spread the bottom of a baking dish with a little oil.
Spread half the courgettes in a layer on the bottom of the dish and smooth until level, cover with half the tomato sauce and sprinkle over 15 ml Parmesan.
Make another layer with the remaining courgettes, topping it with the rest of the sauce and remaining Parmesan.
Place the dish at the top of the oven and bake at 200 ºC for 15 minutes, or until the cheese has melted and turned golden brown.
After removing the dish from the oven, allow it to settle for 10 minutes before serving.