Prepare the red lentils according to the packet instructions. Peel the carrot and shallot and chop finely, then chop the spring onions finely. Sauté the vegetables together in a little oil, remove the pan from the heat and leave to cool. Crumble the toast into breadcrumbs and chop the cilantro and parsley finely.
Mix everything together with the cooked red lentils, add the egg yolk and knead into a thick mixture. Add the spices and season with salt and pepper. Create burger patties from the mixture and fry in hot oil until golden brown.
Mix the sour cream with a little lemon juice until smooth. Chop the parsley and chives finely and stir into the sour cream. Season the dip with salt and pepper and set aside.
Wash the tomatoes and cucumber, peel the red onion and cut everything into thin slices. Shave the Parmesan into thin slices. Place a washed salad leaf on the bottom burger bun and dress with a tablespoon of the sour cream.
Place the fried lentil patties on top. Dress the burger to taste with tomato, cucumber, onion and grated Parmesan.