In a medium bowl, combine cole slaw
mix, yogurt, scallion, 1/4 tsp of the salt and
the black pepper. Cover and refrigerate.
Place flour, egg whites and panko in
separate shallow dishes. Whisk remaining
1/2 tsp salt into flour. Coat each piece of
fish with flour, egg white and panko.
In a large nonstick skillet, heat oil over
medium-high heat. Cooking in batches,
sauté fish 2 minutes per side, until golden.
Place on a wire rack and keep warm.
Heat a stovetop grill pan to medium-high.
Slice avocado in half; remove skin
and pit. Grill 2 minutes per side. Thinly
slice, then place on a plate.
Gently heat tortillas in microwave.
To assemble tacos, double up tortillas
and place a few pieces of fish, some slaw
and some avocado on each. Garnish with
cilantro, tomatoes and onion, if using.
Serve with lime wedges, hot sauce and
sour cream, if using.