Clean, wash and cut the peppers into pieces. Wash the potatoes thoroughly and cut them in half or quarters. Peel onion and garlic. Chop onion coarsely, chop garlic. Wash herbs, shake dry.
Dab meat dry. Fry well all around in hot clarified butter. Season with salt and pepper. Add rosemary and fry over a low heat for 15-17 minutes.
Heat the oil in a frying pan. Fry the potatoes in it over high heat while turning for about 5 minutes. Fry onion, bell pepper, garlic and thyme briefly. Add tomato paste and sauté. Season with salt, pepper and cayenne pepper.
Add a good 1/4 l water, ketchup and stock. Bring to the boil, cover and stew for about 15 minutes.
Wrap meat in aluminium foil and let it rest for about 5 minutes. Dissolve the meat with 4-5 tablespoons of water and pour the meat juice from the pork tenderloin into the vegetables. Season to taste. Cut the meat open, arrange everything.
Drink tip: cool rosé wine, e.g. Cabernet Sauvignon Rosé.