Heat enough olive oil, to shallow fry the fish, in a large skillet over medium-high heat
In a shallow dish, whisk together 1/2 cup of the flour, beer, egg, and baking powder. Place remaining 1/4 cup flour in a separate shallow dish.
Season both sides of fish fillets with salt and black pepper. Dredge fish in flour, turn to coat both sides and then shake off excess flour. Dunk fish in beer mixture and turn to coat both sides.
Add fish to hot oil and cook 2 to 3 minutes per side, until cooked through and opaque. Remove fish from oil. Place on a paper towel lined plate.
While the fish is frying, in a medium bowl, whisk together lemon juice and chili paste. Add mandarin oranges and cilantro and toss to combine. Serve sauce over fish.