Rinse the beans. Drain the beans and tuna. Clean, wash and chop the peppers. Clean, wash and cut spring onions into rings. Peel, halve and cut the red onion into strips.
Mix vinegar, salt and pepper. Fold in 3 tablespoons of oil. Mix with the prepared salad ingredients.
Wash the schnitzel and dab dry. Heat 2 tablespoons of oil in a large frying pan. Fry the cutlets in it on each side for about 3 minutes. Season with salt and pepper and serve with the bean salad.