Heat oil in a skillet, add onion and saute for 10 minutes. Add tomato paste and stock and stir until well blended. Bring to a boil then reduce the heat to low. Add garlic, paprika, red pepper, vinegar, sugar and salt and simmer for 4 minutes. Taste and add more sugar or red pepper as needed. Remove from heat and stir in the herbs. Let cool to room temperature. The sauce will keep for 5 days.`