Clean, wash and cut the peppers into large cubes. Peel and finely dice onions and garlic. Wash the oregano and remove the leaves.
Heat the oil in a pot. Fry the onions and garlic until transparent. Add paprika and oregano and steam briefly. Deglaze with 600 ml water, bring to the boil and stir in the stock. Cover and simmer for 20-25 minutes.
Cut olives into rings. Finely puree the peppers in the broth with a hand blender. Season to taste with salt, cayenne pepper and vinegar.
Arrange the soup in bowls. Spread 1 teaspoon of pesto and the olive rings on each. Garnish with oregano leaves.