Place the beans and juice in a food processor; as it is blending, add the cumin, garlic and salt. Blend til smooth, stopping to scrape down the sides, as needed. Add the cilantro or parsley and blend for another couple of minutes. Spread over the tortilla. Arrange the spinach, peppers, olives and onions on top. Roll the tortillas as tightly as you can. Slice into 2-3 inch pieces. Serve on a plate with the cut size up.