In a bowl, mix together all of the ingredients for the remoulade sauce and refrigerate until you are ready to serve.
In a bowl, mix together the flour, baking powder, pinch of salt, cayenne pepper, and Old Bay seasoning. Slowly whisk in the beer until the batter is thick and free of any lumps.
In a pot heat the oil over medium heat. (Make sure the oil is hot before adding the fish.)
Coat the fish in cornstarch and dip the fish into batter (allowing the excess to drip off) and then slowly immerse the fish into the hot oil. Work in batches if needed as to not overcrowd the oil.
Cook for 2-4 minutes and gently turn the pieces of fish over and cook until golden brown, about another 2-3 minutes. Drain the fish on a paper towel-lined plate or roasting rack. Serve with lemon wedges, chips (see recipe) and remoulade on the side.