In a medium saucepan, heat olive oil over medium heat.
Add garlic and onions and heat until the garlic becomes fragrant and just starts to sizzle, and the onion is translucent.
Add the rest of the ingredients, stir and reduce heat to low.
Cover and let simmer for about 45 minutes, stirring often and adding water if necessary.
Remove from heat, remove bay leaf and let it cool for a few minutes.
Pour all in a food processor and mix until you get the desired consistency.
This sauce can be kept 1 week in the fridge, after which you can freeze it.