Soak the chilies in boiling water for 15-20 minutes. Transfer to a blender jar along with garlic, tomato puree and diced onion.
Also add the brown sugar, vinegar, oregano, cumin, salt and pepper.
Blend for a few minutes until you get a slightly coarse paste.
Transfer to a pan with 1-2 teaspoon neutral oil and cook down the mixture for 10-15 minutes or until it thickens.
Take off heat, allow it to cool down completely and transfer to a jar.
Notes
Use dried chipotle, guajillo, and ancho chilies for a smoky, slightly sweet sauce with layers of rich chili flavor.
Remove the tough stems from the dried chilies before soaking. You can also remove some of the seeds if you prefer a milder sauce.
Soak the chilies in boiling water for 15–20 minutes, or until they are completely softened. This makes them easier to blend into a smooth paste.
Start with fewer chipotle peppers and adjust according to your preferred spice level, as the heat can vary between batches.
Use tomato puree rather than concentrated tomato paste to get the right consistency and balance of flavors.
Blend the ingredients into a slightly coarse paste, or process for longer if you prefer a smoother adobo sauce.
Add a tablespoon or two of fresh water if the mixture is too thick to blend, but avoid adding too much since the sauce should have a concentrated consistency.
Cook the blended mixture over low to medium heat, stirring frequently to prevent it from sticking or burning as it thickens.
Adjust the vinegar, brown sugar, and salt to balance the smoky, tangy, and slightly sweet flavors.
Use this homemade chipotle in adobo in tacos, burritos, chili, marinades, soups, or creamy dips. Start with a small amount and add more to taste.
Store the cooled sauce in an airtight container in the refrigerator for up to 3–4 days, or freeze it in small portions for longer storage.
This recipe is not suitable for room-temperature storage or home canning without a tested preservation method.