Finely dice the bacon. Clean and wash spring onions and cut into rings. Peel, wash and roughly dice carrots. Peel, wash and cut potatoes into small cubes. Leave bacon out in a pot.
Add oil, heat up. Add the potatoes, carrots and spring onions, fry while turning. Deglaze with 600 ml water. Add lentils, bring to the boil, cover and cook over medium heat for about 15 minutes.
Then season with salt, pepper, sugar and vinegar. In the meantime, wash the fish and pat dry. Heat clarified butter in a pan. Add the fish and fry on each side for about 3 minutes, season with salt and pepper.
Remove from the pan. Deglaze frying fat with lemon juice, bring to the boil. Arrange lentil vegetables and fish on plates, drizzle with frying fat. Garnish with lemon wedges.