Peel and finely dice the onion and garlic. Heat the oil in a pot. Sauté onion and garlic in it. Stir in the tomato paste, sweat it on and deglaze with tomatoes. Bring to the boil, puree finely and season to taste with salt, pepper and sugar.
Simmer covered for 3-4 minutes. Clean and wash the chilli pepper. Cut the pod into rings, removing the white seeds. Cut olives into slices. Wash thyme, dab dry, pluck leaves from the stalks except for a few for garnishing.
Add thyme leaves, olives and chilli rings to the sauce and continue cooking for 1-2 minutes. Arrange the sauce in a sauce boat and garnish with thyme leaves.