Preheat the oven to 190 °C. Grease the oven dish with butter or olive oil.
Peel the potatoes and slice thinly. Boil the potatoes in boiling water for 3 minutes. Drain and rinse under cold running water to stop the cooking process.
Boil the mangetout in boiling water for 2 minutes. Drain and rinse under cold running water.
Divide the potato slices evenly over the oven dish and arrange the mangetout on top.
Beat the eggs with the cooking cream and the Herbes de Provence in a bowl with a whisk. Press the garlic. Add to the egg mixture and season with salt and pepper. Pour the egg mixture over the vegetables. Sprinkle over the grated cheeses. Bake the dish in the middle of the oven for about 30 minutes until golden brown and bubbling.
Serving tip: Tasty with a fresh green salad for a vegetarian meal or with the meat of your choice.
