Wash the roast and pat dry. Season all around with salt and pepper. Place on the greased fat pan of the oven. Roast in the preheated oven (electric: 200 °C/ gas: level 3) for about 1 1/4 hour. Peel and quarter onions and place them on the fat pan.
Deglaze roast 20 minutes before the end of the cooking time with 1/4 litre of water. Meanwhile, for the vegetables, peel and wash the carrots and kohlrabi and cut them into small pieces. Cook both in boiling salted water for about 12 minutes. Clean and wash spring onions and cut them into pieces of about 3 cm length. Cook for 5 minutes with the remaining vegetables, then drain. Wash and puree the herbs. Melt the fat just before serving. Swivel vegetables and herbs in it. For the gravy, dissolve the gravy. Puree with the onions, bring to the boil briefly.
Melt the fat just before serving. Swivel vegetables and herbs in it. For the gravy, dissolve the gravy. Puree with the onions, bring to the boil briefly. Add cream, sprinkle with sauce thickener. Bring to the boil again and season with salt and pepper. Serve roast, vegetables and sauce garnished with fresh herbs