Wash the asparagus, cut off the woody ends. Peel and wash the potatoes and slice them finely. Grease an ovenproof dish. Layer prepared vegetables in it. Whisk cream, crème fraîche, eggs and egg yolk. Season with salt and pepper.
Pour over the vegetables. Bake in the preheated oven (electric oven: 200 °C/ gas: level 3) for about 45 minutes. In the meantime, cut tomato crosswise, blanch, skin, cut into eight pieces and remove seeds. Cut tomato into small cubes. Sprinkle on gratin before serving. Garnish as desired with tomato wedges and chervil
Form: Pillivuyt