2While the chiles rehydrate, heat a comal or heavy skillet over medium heat. Add the Roma tomatoes, White onion, and Garlic cloves. Roast, turning occasionally, until softened and lightly charred, about 10-12 minutes.
3Drain the rehydrated Ancho chiles and place them in a blender with the roasted Roma tomatoes, White onion, and Garlic cloves. Add 250 grams of the Fish broth and blend until very smooth.