Add the tomatoes, poblano, onions and garlic cloves to the prepared baking sheet. Toss with the oil to coat, and sprinkle with salt. Roast for 15 minutes. Remove the garlic, flip the poblano over, and continue roasting until the poblano and onions are charred and the tomatoes are soft and beginning to split, another 15 minutes. Let cool for at least 20 minutes.
Peel the garlic and remove the skin and stem from the poblano (remove the seeds, too, for a milder sauce).
In a food processor, combine the roasted vegetables, cilantro, vinegar, adobo sauce, coriander, cumin and 1/2 teaspoon salt. Process until evenly combined but still with some texture, similar to crushed canned tomatoes. Pour into a large saucepot and stir in the tomato puree and chicken stock. Bring to a boil and cook for 2 to 3 minutes, just to combine the flavors. Remove from the heat and season with salt. |