Dry toast the dried chili peppers (stemmed and seeds removed) in a heated pan over medium heat. Toast them a couple minutes per side, until they start to puff up slightly.
Cool, then set them into a heavy bowl with enough hot water to cover them.
Let them soak for 20 minutes, or until they become very soft. Remove them and place them in a blender or food processor.
Reserve 1 cup of the dark soaking water.
In the same heated pan, add the olive oil. Cook the onion about 3 minutes, or until they become translucent.
Add the garlic and cook another minute, until they become fragrant.
Add them to the food processor along with the sea salt.
Pour in the reserved soaking liquid and process to form a sauce. It will be very thick at this point.
Add in more water, a half cup at a time, until you achieve your desired consistency.
Strain, if desired, and serve as needed.