Preheat your broiler to high. Place the tomatoes, tomatillos, onion, and garlic on a sheet tray. Broil for around 20 minutes, turning halfway through. The garlic will be ready sooner (about 12–15 minutes). Remove garlic paper once cooled and reserve everything.
Heat a comal or cast iron pan to medium heat. Toast all chiles, moving constantly, until fragrant and slightly darkened. Place in a bowl and cover with boiling water. Let steep for 20 minutes until tender, then strain.
Add the chiles, onion, and garlic to a blender with enough steeping liquid to form a smooth paste. Add the roasted tomatoes and tomatillos and blend on low until mostly smooth — leave a little texture!
Transfer to a pot and cook over medium heat, stirring, until it reaches a tomato paste-like consistency. Cool, then stir in the soy sauce, Worcestershire, Maggi, and piloncillo. Taste and adjust as needed.
