Heat oil in a pan; add the onion, garlic and cook till the onions are transparent.
Add the spinach, ground cumin, chili powder, oregano, salt and pepper. Cook till the greens are wilted, about 3~4 minutes.
Add the black beans and cook for another 3~4 minutes. Check the seasoning and turn off the heat. Add the grated cheese and mix well.
Preheat the oven to 375°F. Line a baking sheet with parchment.
Open the tube of crescent rolls. Press the perforations to seal. Divide the dough into equal quarters.
Place 3~4tbsp filling in the center of the dough. Bring one side of the rectangle over the filling and roll up. Press the sides to seal and place them seam side down on the prepared baking sheet.
Bake for 15~18 minutes or until the buns are golden brown. Cool for 10 minutes and serve warm with salsa and sour cream.