Peel, wash and chop the potatoes. Clean, wash and slice the carrots. Clean, wash and slice spring onions, cut half into pieces, the rest into fine rings. Wash pork tenderloin and dab dry.
Coarsely chop the peanuts. Mix mustard, crème fraîche, salt and cayenne pepper. Add the spring onions cut into rings. Turn pork fillet first in the crème fraîche, then in the nuts and place on the fat pan of the oven.
Mix potatoes, carrots and spring onions and also put them on the fat pan, sprinkle with salt and pepper. Bake everything in the preheated oven (electric cooker: 175 °C/ gas: level 2) for 40-45 minutes.
Bring the stock to the boil and after half the baking time, add the hot stock to the fat pan. Arrange sliced pork fillet and vegetables on a plate and serve garnished with parsley and tomato rose as desired.