Heat oil in a large skillet or sauté pan over MEDIUM heat. Add the onion and sauté until tender, about 3 minutes. Add the chicken and sprinkle the cumin, paprika, coriander, oregano, salt, and pepper over the top. Cook, stirring for a minute or two to distribute the seasoning.
Add the broth and tomato paste and stir until well combined. Bring the mixture to a simmer then reduce heat to LOW and allow it to cook down for 4 to 5 minutes, or until most of the liquid has been absorbed.
Serve chicken on toasted tortillas with black beans and any (or all!) of the toppings.
