Clean and wash the beans and break them into bite-sized pieces. Cook in little boiling salted water for 15-20 minutes. Peel, wash and slice the potatoes. Cook in little boiling salted water for about 10 minutes.
Meanwhile roast sunflower seeds in a pan without fat. Drain the bean seeds on a sieve. Peel and halve the onion and cut into thin rings. Wash parsley, dab dry and chop.
Drain the potatoes and green beans on a sieve. Heat the oil in a pan, sauté the onions and add the tomato sauce. Stir in thyme, savory and parsley, bring to the boil and simmer for about 5 minutes.
Season to taste with salt and pepper. Mix the vegetables into the tomato sauce and place in an ovenproof dish. Sprinkle with sunflower seeds and cheese. Bake in the preheated oven (electric oven: 200°C/ gas: level 3) for 25-30 minutes.