Pour black beans and their juice into a small saucepot over medium heat; cover and simmer until hot. This usually takes only 10 minutes, but if you forget you can also heat them quickly over high heat in under 5 minutes or in the microwave.
In a large cast iron skillet (or any other non-nonstick skillet) sauté onions in 1-2 tablespoons olive oil over medium heat until they release their juices and begin to turn translucent. Add garlic and chipotle peppers, stir frequently and continue to cook over medium heat until the onions are almost translucent. Remove onion mixture from the skillet to a small bowl and set aside.
In the same large skillet brown chicken and chorizo sausages until completely cooked. Drain of any excess fat.
Add the onion mixture back into the pan, stirring to mix. Add ½ cup water or broth, tomato paste and spice mix. Stir to evenly coat the meat with the spices.
Cook for about 5 minutes until most of the water has been evaporated. Taste for spice. Add more if desired.
Turn off the burner you used to cook the filling. Toast the tortillas directly on the hot burner or in a flat bottomed pan, just until each side has crisped and begun to bubble.