Saute onion and garlic in oil. Saute until ingredients are translucent. This cooking on low to medium heat makes the onions and garlic sweeter and more flavorful.
Add in other ingredients except optional add-ins. Cook over medium heat,stirring frequently until mixture comes to a boil. Reduce heat and let simmer for 20 minutes stirring occasionally.
Remove from heat and allow to cool. The sauce will thicken as it cools.
Store in an airtight container or jar in the fridge for up to 3 weeks.