Heat oil over medium high heat in a large sauce pan or skillet. Add onions and sauté, and stir continuously for 4-5 minutes. Turn heat down to medium low and add garlic. Sauté 6-7 more minutes, stirring and cooking until golden and translucent.
Add tomato paste and let it brown in the skillet for about 1-2 minutes turning heat up a bit.
Add water and stir to incorporate.
Add vinegar, soy, molasses, brown sugar and generous pinch salt and pepper.
Cook for 3- 4 minutes, stirring occasionally.
Add canned chipotle pepper in Adobo sauce ( THE SAUCE ONLY) one tablespoon at a time. SEE NOTES. Cook only for 5-10 more minutes. Let cool and store in a mason jar in the fridge.
NOTES: This will not only add heat, it will add smokiness. If you can’t find this, you can sub chipotle powder to taste, or smoked paprika and chili powder to taste. You can also add liquid smoke for extra smokey flavor – using very conservatively, adding more to taste.
Store in a jar in the fridge. Keeps up to 2 month.