In a medium bowl, start by combining Bisquick mix, cornmeal, salt and pepper until the blend is uniform.
Gradually stir in beer to create a thick paste that can be adjusted with more beer if desired.
Whisk one egg in a separate bowl till it's smooth before folding it into the mixture.
Cut fish fillets into 2-inch cubes or strips, then dip them in the batter to make sure each piece is fully covered. Place them on wax paper in an even layer on a baking sheet.
When the oil reaches 350 degrees Fahrenheit, slowly drop the battered fish pieces into it and fry for 3 minutes until golden brown.
Move the cooked fish onto a cooling rack lined with paper towels and top them with a generous drizzle of tartar sauce while still warm. Serve warm alongside your favorite sides for the perfect meal.