In a Dutch oven, heat oil to 375 degrees F.
Fry potatoes until golden brown, roughly 10 minutes removing with a slotted spoon or spider. Hold in low oven to keep warm while cooking the fish.
Preheat oven to 225 degrees F.
In a large bowl, pour in 1 bottle of beer. Sift 1 1/2 cups flour into the bowl, whisking in gently until just combined, stir in House Seasoning. Pat fish dry and season on both sides with salt and pepper and coat the fish in the beer batter. Dredge the pieces of fish in 1/2 cup of remaining flour and slide into oil as coated. Fry fish, turning over frequently, until deep golden and cooked through, 4 to 5 minutes. Transfer to a paper towel-lined baking sheet and keep warm in oven. Fry remaining fish in batches, returning oil to 375 degrees F between batches.
Serve fish with French fries.
Mix ingredients together and store in an airtight container for up to 6 months.