Peel and wash the potatoes and cook them in boiling salted water for 20-25 minutes. Clean, wash and cut broccoli into small florets. Peel carrots and cut them into thin slices, possibly halving large slices.
Onions peel and cut into small pieces.
Cook the carrots in boiling salted water for about 6 minutes. Add the broccoli florets about 4 minutes before the end of the cooking time. Heat 1 tablespoon of oil in a frying pan. Sauté the onions for 3-4 minutes while turning, remove from heat and allow to cool.
Drain the potatoes in a sieve, put them back into the pot and let them evaporate briefly. Press the potatoes through a potato ricer. Mix egg yolks and starch with your hands (or a wooden spoon) into the potato mixture.
Then carefully fold in carrots and broccoli. Season vigorously with salt and pepper.
From the potato mass with wet hands. Form approx. 14 roasts (approx. 7 cm Ø: approx. 1.5 cm high). Heat 4 tablespoons of oil in portions in a large frying pan. Fry the roasts for 2-4 minutes on each side, remove from the pan and place on a baking tray lined with baking paper.
Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for 6-8 minutes.
For the dip, stir the quark crème fraîche and milk until smooth. Wash the sprouts, drain well and, except for a few for garnishing, mix into the quark mixture. With cayenne pepper
Prepare the roasts and sprout dip. Dust the dip with cayenne pepper and sprinkle with the remaining radish sprouts.