Onions peel, 1 onion finely dice. Wash and chop the tomatoes. Mix vinegar, salt, pepper and 1 pinch of sugar. Fold in 3-4 tablespoons of oil. Mix with diced onions and tomatoes.
Wash the lemon, grate dry and cut in half. Squeeze one half, cut the rest into slices. Wash the fish, dab dry. Cut into 8-12 pieces. Sprinkle with lemon juice, let it steep a little.
Rinse the beans and let them drain. Wash and chop the parsley. Peel garlic. Chop the remaining onions and garlic finely. Sauté in 1 tbsp. hot oil in a saucepan. Add beans, approx. 100 ml water and broth, bring to the boil.
Pull the pot off the stove. Finely mash the beans with a hand blender. Season to taste with salt and cayenne pepper, keep warm.
Season fish with salt and pepper. Heat 2 tablespoons of oil in a large coated frying pan. Fry the fish in it in portions on each side for about 2 minutes. Season tomato salad to taste again. Arrange everything, sprinkle with parsley.
Garnish with lemon wedges.