Peel and wash the potatoes and cut them into thin slices. Cut garlic in half. Spread garlic on the gratin dish, grease and layer potatoes in flakes. Season cream with salt, pepper and nutmeg and pour over potatoes.
Cook in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 45 minutes. Wash, clean and halve the beans. Wash the thyme. Cook the beans and thyme in little boiling salted water for about 15 minutes.
Wash the meat and dab dry. Rub a large pan with 1 teaspoon of oil, heat it up. Fry the fillets for 4-6 minutes while turning. Drain the beans and let them drain. Peel onions and shallots.
Cut onions into slices. Heat butter in a pan. Brown the onions and shallots in it. Add the beans, toss briefly. Season meat with salt and pepper, cut into slices.
Arrange meat, gratin and bean vegetables on plates.