Onions peel and cut into fine slices. Clean and wash the mushrooms. Clean, wash and slice the tomatoes. Clean, wash and pluck the rocket into bite-sized pieces. Heat the fat. Fry the mushrooms for about 4 minutes, turning them carefully. Season with salt and pepper and put aside.
Heat the oil in the frying fat. Fry the onion slices in it at high heat until golden brown. Add tomatoes, season with salt and crushed chilli. Fry for another 2 minutes. Fold in mushrooms, rocket salad and olives. Arrange in small bowls and serve