Combine cornmeal, flour, ground chili powder, cayenne to taste, garlic powder, salt, and pepper on a shallow dish.
Coat each fillet in the beaten egg, then dredge in the cornmeal mixture.
Place breaded fillets in a single layer on a plate, cover, and refrigerate for at least 30 minutes to set breading.
In a skillet over medium-high heat, melt 1 Tbsp of the butter together with the oil.
Take chilled fillets from refrigerator and brown them until golden brown on each side and cooked through, about 4 to 6 minutes per side.
Transfer cooked fish to serving plates.
Over low heat, heat remaining butter in the same pan you cooked the fish in; sauté the minced onion and minced garlic clove for 3 minutes, then stir in the hot pepper sauce, making sure to scrape the bottom of the pan with a spatula to get up the cooked bits.
Divide the sauce between the 4 servings and drizzle over the fillets.
Serve fillets immediately with good blue cheese dressing and celery sticks.