Achiote Sauce

1 tbsp unsalted butter
1 onion, roughly chopped
3 garlic cloves, minced
1 1/2 tbsp tomato paste
1 1/2 tbsp Achiote paste, crumbled,
2 cup chicken stock
1 tsp salt
2 tsp freshly-cracked black pepper
2 tbsp white vinegar

In a medium saucepan, over medium-low heat melt the butter. Cook the onions until soft and translucent, 12 to 15 minutes.

Stir in the garlic, tomato paste, and Achiote paste and cook an additional 3 to 5 minutes, stirring frequently.

Add the chicken stock, salt and black pepper. Bring to a boil, reduce to a simmer and cook, stirring and skimming frequently, 12 to 15 minutes.

Add the vinegar and cook for 2 to 3 minutes.

Puree in a blender or food processor. Store in refrigerator for 2 to 3 days.