Preheat oven: electric cooker: 225 °C/circulating air: 200 °C/ gas: stage 4 Wash chives and cut into small rolls. Mix sour cream, mayonnaise and chives (up to 1 tablespoon) and season.
Cut the baguette in half. Cut each half horizontally. Spread the breads with herb butter and roast in a hot oven for about 8 minutes. Wash and slice the tomatoes.
Peel onions and cut them into rings. Pat the steaks dry. Heat oil in a large pan. Fry the steaks in it in portions on each side for about 1 minute. Season with salt and pepper.
Cover bread with steaks, tomatoes and onions. Spread chive cream on top and sprinkle with the remaining chives. Olives go well with it.