Preheat oven to 425°F. Place a rack on a baking sheet and coat with cooking spray.
Put the tortilla chip crumbs into a large zipper-lock bag. Place the egg in a shallow dish. Sprinkle fish fillets with 1/4 tsp. salt, then dip into the egg and transfer to the bag. Seal and shake until all fillets are coated. Transfer the fish to the prepared rack. Bake for 15-18 minutes, or until crumbs are lightly browned and fish flakes easily.
In a medium bowl whisk together the juice of one lime, olive oil, and 1/4 tsp. salt. Add the broccoli slaw mix and toss. Serve with the fish, lime quarters, and, if using, the salsa.