Peel and chop the onion and garlic. Halve, clean, wash and chop the peppers. Wash the tomatoes. Dab meat dry, cut in half crosswise, season with salt and pepper and turn in flour.
Heat 4 tablespoons of oil in a large frying pan and fry the steaks for about 2 minutes on each side. Spread the steaks in an ovenproof dish. Steam vegetables in hot frying fat for about 3 minutes, season with salt and pepper and deglaze with wine.
Spread the vegetables over the steaks. Braise in the preheated oven (electric cooker: 175 °C/ circulating air: 150 °C/ gas: see manufacturer) for about 2 hours. Cover the last 30 minutes with foil.
In the meantime, peel and wash the potatoes and cut them roughly into pieces. Cover the potatoes and cook in boiling salted water for about 20 minutes. Chop olives finely. Warm up the milk. Drain potatoes. Add butter, 4 tablespoons of oil and warm milk and mash coarsely.
Stir in the olives. Season mashed potatoes with salt and pepper. Take steaks with vegetables out of the oven, arrange. Add mashed potatoes.