Cut out and discard the core from the cabbage; quarter the cabbage lengthwise, then thinly slice crosswise and transfer to a large bowl.
Small dice the tomatoes and add to the cabbage.
Halve and pit the avocados; cube the flesh while still in the skin. Scoop out the flesh into a small bowl.
Shave the cilantro leaves off the stems; discard the stems and mince the leaves. Add ½ of the cilantro to the cabbage and the other ½ to the avocado.
Juice the limes into a small bowl; add ½ to the cabbage and the other ½ to the avocado.
Preheat a grill pan or skillet over medium heat.
Place the fish on a plate, drizzle with olive oil, and season with chili powder, salt, and pepper.
1 ½ lb halibut fillets
2 tbsp extra virgin olive oil
2 tsp chili powder
½ tsp salt
¼ tsp black pepper
Place the fish in the grill pan or skillet; cook until opaque and golden brown, 2 to 3 minutes per side. Once done, transfer to a plate.
Season the avocado with salt and pepper; mash with a fork until smooth.
½ tsp salt
¼ tsp black pepper
Season the cabbage mixture with salt and pepper; toss until well combined.
1 tsp salt
½ tsp black pepper
Place the tortillas on a plate and cover with a damp paper towel. Microwave for 30 to 60 seconds until they are warmed through. (This step is optional.)
16 small corn tortillas
Using your hands or a fork, flake the fish.
Divide the cabbage slaw among the tortillas (leaving any extra on the side), then add the fish, and spoon dollops of the guacamole on top. Enjoy!