Heat the oil on a large skillet. Add the rice and fry until warm. Remove from heat, and transfer to a large bowl. Set aside.
In the same skillet, fry the onion and garlic until the onion is transparent. Melt the butter and add in the chili powder, chipotle powder, cumin, black pepper, cloves and nutmeg.
Add in the black beans and diced tomatoes, and bring to a simmer. Reduce heat to low, and cook until the flavors blend, around 10 minutes, stiring constantly.
Fill each tortilla with 1/2 cup bean mixture and 1/3 cup rice.
(Optional) If you want a more cheesy topping, place in baking pan, top with cheese and place in the oven for 15-20 minutes at 350˚F