Add dried chiles to large heavy-bottomed Dutch oven or stock pot and cook over medium-high heat, stirring frequently, until slightly darkened with intense, roasted aroma, 2 to 5 minutes. Do not allow to smoke. Remove chiles to small bowl and set aside. Alternatively, place dried chiles on a microwave-safe plate and microwave on high power in 15-second increments until pliable and toasted-smelling, about 30 seconds total. Transfer to a 2-quart microwave-safe liquid measuring cup or bowl. Add half of chicken broth and chipotle chiles, cover with plastic wrap, and microwave on high power until gently simmering, about 5 minutes. Remove from microwave and set aside for 5 minutes. Transfer chiles and liquid to blender and blend, starting on the lowest possible setting and gradually increasing speed to high (make sure to hold the lid down with a clean kitchen towel or a potholder to prevent it from blowing out). Blend until smooth, about 1 minute.