Preheat oven to 350 F
Heat medium/small pot on medium heat. Add oil and flour and whisk to make roux. Add broth and seasonings. Let sauce come to a boil and thicken for about 5 minutes
In medium/large skillet, add bell pepper, black beans, green chiles and 1/2 cup of the sauce. Combine and heat for 3-5 minutes
Add 1/2 cup sauce to the bottom of a 9x13 pan
In each tortilla, add 1/4-1/3 cup black bean mixture and about 2 Tbsp cheese (no need to measure). Roll tightly and place with the end of the tortilla side down to keep enchiladas in tact. After the 10 enchiladas are in the pan, add the remaining sauce, about 1/2 cup cheese, and olives to the top
Bake for 10 minutes until cheese on top is melted
While enchiladas are baking, chop and combine onion, cilantro and tomato in a small bowl. Add lime juice and salt.
When enchiladas are done baking, top with Pico de Gallo, avocado, sour cream and enjoy!