In a saucepan, heat olive oil over medium heat.
Add diced yellow onion and cook under tender and translucent.
Add rest of ingredients and stir to combine.
Bring to boil, then reduce heat to low and simmer for 20 minutes. Move ingredients to food processor to puree, or use immersion blender.
Remove from heat and let cool completely.
Transfer to glass jar and store in refrigerator until ready to use, will keep for 6 days.