Wash the potatoes, bring to the boil covered with water and cook for 20 minutes. Dice bacon. Peel and finely dice onions. Leave the bacon out in a pan, fry the diced onions briefly. Add stock and vinegar and bring to the boil. Season to taste with mustard, salt and pepper.
Drain potatoes, rinse and peel them, let them cool down a bit and cut them into slices. Pour bacon-onion marinade over the potatoes. Wash parsley and dill, keep some for garnishing. Finely chop the rest. Fold the herbs into the salad and leave to soak for 1 hour. In the meantime, wash the fish, cut into 4 pieces and sprinkle with lemon juice. Separate the egg. Stir egg yolk, beer, flour and 1/2 teaspoon salt until smooth. Beat egg white until stiff and fold in. Heat the fat in the deep fryer to 180°C. Season fish with salt and pepper, dip into the batter and bake in hot fat until golden brown.
In the meantime, wash the fish, cut into 4 pieces and sprinkle with lemon juice. Separate the egg. Stir egg yolk, beer, flour and 1/2 teaspoon salt until smooth. Beat egg white until stiff and fold in. Heat the fat in the deep fryer to 180°C. Season fish with salt and pepper, dip into the batter and bake in hot fat until golden brown. Season potato salad again and arrange it on a plate with the fish. Garnish with the remaining parsley, dill and lemon wedges
Preparation time approx. 1 1/4 hours