Preheat the oven to 425˚F.
Rub the salmon with chili powder, cumin and salt and place skin side down on a parchment-lined baking sheet.
Roast for 10 minutes per inch, or until just opaque—the thinner end should flake with a fork, but you want some moisture in the thicker middle.
Meanwhile, thinly slice the cabbage and toss it with the mayonnaise, vinegar and a pinch of salt.
Warm the tortillas (wrap them in foil and slide into the oven for a few minutes) and serve them with the slaw, flaked salmon, sliced avocado, chopped pineapple and fresh cilantro.