Bring a kettle of water to boil. Place the peppers in a shallow bowl and submerge in hot water. Cover the bowl with a plate to lock in the steam. Allow the peppers to sit until supple and rehydrated, 20 minutes. Remove the peppers and reserve the soaking liquid.

Cut the stems off the peppers and remove the seeds and ribs with your fingers; discard. Roughly chop the pepper and set aside.

Meanwhile, heat the oil in medium saucepan. Saute the onion over medium-high heat until soft and just beginning to brown, 6 minutes. Add the garlic and cook 2 minutes more. Stir in the tomato paste, diced peppers, and ½ cup of the soaking liquid. Cook over medium heat until thickened, 5 minutes. Add the remaining ingredients and simmer until the sauce is the texture of ketchup, 5 minutes more.

Transfer to a blender and puree until smooth. Taste for seasoning and add more salt as necessary. Store in an airtight container in the fridge for use on pulled pork, chicken fingers, or ribs.