Peel, wash and chop the potatoes. Peel the celery and cut into equally large pieces. Cook potatoes and celery in salted water for about 20 minutes until soft. Heat milk and 30 g butter in a small pot.
Peel onions and cut 3 onions into rings. Turn onion rings in 2 tablespoons of flour. Heat 4 tablespoons of oil in a frying pan. Fry the onions until crisp and brown. Drain on kitchen paper.
Melt 20 g butter in a small pot and sauté 1 tbsp. flour in it. Deglaze with vegetable stock and white wine. Bring sauce to the boil and simmer for about 5 minutes. Finally stir in sour cream, season with salt, pepper and lime juice.
Keep the sauce warm.
Dice 1 onion. Cut the bacon into fine cubes and leave them crisp in a pan without fat. Add onion and peas and fry for about 3 minutes. Mix peas and sauce. Drain potatoes and celery and mash them coarsely.
Mix with the butter mixture. Season with salt and nutmeg.
Cut the meat loaf into slices. Heat 2 tablespoons of oil in a frying pan and fry the Leberkäse for about 2 minutes on each side. Arrange Leberkäse, peas and mashed potatoes on plates. Sprinkle the mashed potatoes with fried onions.