Finely chop the onion. Sauté half in 1 tablespoon of oil in a casserole dish, deglaze with 250 ml broth and bring to the boil. Stir in red lentils and simmer covered for about 10 minutes. Blanch cabbage leaves in boiling salted water for about 3 minutes, remove, rinse with cold water and drain
Bake the potato balls on a baking tray in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 15-20 minutes. Dice the tofu finely. Remove the coriander leaves, chop finely and fold into the lentils with the tofu and curry. Pour the lentil mixture onto the cabbage leaves and roll up firmly. Wrap each with a leek straw.
Heat the rest of the oil in the pot and braise the remaining onion and roulades in it. Deglaze with the remaining stock and stew covered over a low heat for about 15 minutes. Arrange roulades with stock on a plate. Add potato balls. A spicy horseradish cream sauce tastes very good with it