For the beer batter and cod: Portion cod into pieces weighing approximately 2 ounces each.
Pour beer into a large bowl. Add eggs, garlic powder, onion powder, seafood seasoning, baking powder, salt, pepper and cayenne, then add cornstarch. Whisk in flour until batter is smooth and thick (like pancake batter).
Heat oil in a fryer to 350 degrees F. Lightly flour each piece of cod, then dip in beer batter and fry until crispy and golden brown, 5 to 7 minutes.
For the tartar sauce: Combine mayonnaise, dill relish, parsley, pepper and salt in a large bowl. Process celery, onion, lemon juice and hot sauce in a food processor until onion and celery are very finely chopped. Add contents from the food processor to the bowl. Mix together until well incorporated.
Serve fish with French fries, coleslaw, tartar sauce and lemon slices.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.