Let's start with the BBQ slaw so that it can be marinating while we prepare the taco filling. In a medium sized bowl, combine the shredded purple cabbage, BBQ sauce, mustard and olive oil. Toss gently until all of the cabbage is evenly coated in the sauce, then set aside.
Start to heat your griddle on a medium-high heat setting and spray the olive oil across the surface. Place the black beans on one side, the diced pineapple on the other. You'll want the pineapple to get brown on each side. Add little bits of water to the black beans if they begin to dry out in the cooking process.
Meanwhile, rinse your cilantro and pinch off as much as you'd like to use for a topping and set aside in a small bowl. Warm up your tortillas if necessary.
Now, assemble! Black beans first (add a little salt and pepper to them too!), then pineapple, and top with BBQ slaw and cilantro :)