Wash the potatoes thoroughly, put them in a pot with water, bring to the boil and cook for about 20 minutes. Drain, let cool a little, peel and slice the potatoes. In the meantime clean, wash and dice the peppers.
Clean and clean the mushrooms and cut them into large slices. Peel and finely chop the onion. Peel garlic and chop finely. Wash the meat, dab dry and cut into strips (shredded type).
Heat the oil in a pan and fry the meat thoroughly, turning it over. Add the onion, mushrooms, garlic and paprika and fry while turning. Season with salt, pepper and paprika, dust with flour, sauté and gradually add stock and milk.
Bring to the boil. Stir in the crème légère. Season again with salt, pepper, paprika and sugar. Pour into one large or 4 small ovenproof casserole dishes. Wash the thyme and shake dry.
Pluck some leaves from the stems. Spread potato slices on top and sprinkle with cheese and half of the thyme. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 45 minutes.
Remove from the oven and serve immediately. Garnish with remaining thyme.