SERVINGS: MAKES ABOUT 2 CUPS
Heat a large dry cast-iron skillet over medium-high heat. Working in batches, toast chiles until slightly puffed and fragrant, 15-20 seconds per side. Let cool.
Using kitchen scissors and working over a medium bowl, cut chiles into thin rings, reserving seeds. Cover with 2 cups very hot water and let soak for 10 minutes.
Meanwhile, heat the same skillet over medium-high heat. Add garlic; cook, turning often, until tender and skin is lightly charred, about 8 minutes. Let cool. Peel; trim ends.
Transfer chiles with seeds and liquid to a blender; add roasted garlic, 1 1/2 tsp. salt, and remaining ingredients. Pulse until a thick, coarse purée forms. Season with salt.