Preparation

• Heat the oil in a 10-inch skillet over medium-high heat. Add the onion, poblano, 1/2 tsp. salt, and 1/4 tsp. pepper and cook, stirring occasionally, until the vegetables begin to sizzle, 2 to 3 minutes. Turn the heat down to low, add the garlic, and cook, stirring occasionally, until the onion is golden, 10 to 15 minutes. Add the cumin, coriander, and cinnamon and cook, stirring, for another 30 seconds.
• Transfer the mixture to a food processor and let cool for a few minutes. Add the chipotle and process until smooth.
• Transfer to a small bowl and stir in the lime juice and sour cream. Refrigerate for at least 1 hour to let the flavors meld. Season to taste with more salt, pepper, or lime juice.

Make Ahead Tips

The sauce can be made ahead and kept in the refrigerator for up to 2 days.