In a bowl combine the flour, cornstarch, paprika and baking powder.
Add the beer and egg, and stir until the batter is evenly combined but still slightly lumpy.
For the Fish:
If using frozen fillets, Thaw out the fish. Pat the fillets dry using paper towels.
Sprinkle the fish with salt and pepper.
In a large skillet heat about 1-inch of oil, over medium heat.
Pour the other 3/4 cup of flour into a shallow dish or onto a plate. Working one peace at a time, put the fish pieces into the flour, turning to coat, and then shaking off any excess.
Dip the flour-coated fillets into the batter.
Fry the battered fish, about four pieces at a time, in the hot oil for 2 to 4 minutes or until crispy and golden, turning once halfway through frying time.
Transfer the fried fish onto a layer of paper towels to drain.
Keep the fried fish warm in the oven, on warm, while frying remaining fish.
Place the cooked fish into/onto heated corn tortillas.
Combine the cabbage mix, green onions, cilantro, vinegar, oil, sugar and salt in a bowl and toss to evenly coat/combine.
Cover and chill until ready to serve, or serve immediately topping each 'taco' with the preferred amount of slaw.