In a food processor add all ingredients except the oil. Process well until every thing is well combined.
After that pour in vegetable oil with processor running until smooth and emulsified.
Pour the mixture in a pot. Heat over high until it starts boiling. Turn the heat to low and simmer for 20 minutes, or until the mixture has reduced to half.
Remove from heat and let cool for at least 15 minutes. Puree once again until smooth in consistency.