Boil the pasta in salted water. Wash the leek and cut into fine rings. Cut the pepperoni into small cubes. Chop the parsley. Roast minced meat in oil, briefly toast the leek, peppers and parsley.
Stir 1/2 cup of pasta water with paprika until smooth, pour over the meat, let it boil briefly and add the spices. Let simmer for about 5 minutes. Fold in the pasta.
Mix the yoghurt with the garlic and salt. Melt butter, stir in 1 teaspoon of paprika and pour over the yoghurt.