Onions peel and roughly chop. Wash the meat, dab dry and rub with salt and pepper. Roll up the meat and tie up with kitchen string
Heat the oil in a frying pan. Brown the rolled roast thoroughly all around, remove. Sauté onions in frying fat for approx. 3 minutes. Add tomato paste and fry for approx. 2 minutes. Deglaze with red wine and stock. Put the roast back into the roaster. Cover and bake in a preheated oven (electric cooker: 175 °C/ circulating air: 150 °C/ gas: see manufacturer) for 1 1/2-2 hours
Peel, wash and cut the carrots into diagonal pieces (approx. 3 cm). Peel, wash, halve and slice the kohlrabi. Clean, wash and halve the sugar snap peas. Cook carrots and kohlrabi in little boiling salted water for 8-10 minutes. Add sugar snap peas about 4 minutes before the end of cooking time. Pour the vegetables into a sieve. Wash the chervil, shake dry. Pluck off the leaves and chop them, except for a little to garnish. Heat the fat in a pan and briefly toss the vegetables in it. Season to taste with sugar, salt and pepper. Mix the chervil into the vegetables
Remove the roast from the roaster and put it aside covered. Pour frying stock through a sieve into a pot. Mix starch with 2 tablespoons of water and stir into the gravy, bring to the boil and simmer for about 1 minute. Arrange roast with vegetables and sauce on a plate. Garnish with chervil