Season fish pieces on both sides with salt and pepper. Store in fridge on a plate.

Make the batter by whisking the dry ingredients in a medium bowl. Pour in the beer and whisk until smooth. Cover with plastic wrap and hold in fridge for 30 minutes.

Cut potatoes into 1/4 inch matchsticks. Place in a bowl and set aside.

Pour the oil into a large Dutch oven, add all the potatoes and turn heat to medium high. Watch without stirring until the oil is at a full roiling boil. This should take about 6 minutes. Let cook at boil for another 15 minutes without stirring. They should just begin browning and be limp. Stir gently with tongs and cook another 2-3 minutes. Remove potatoes to a sheet pan lined with paper towels.

Keep heat up so that oil comes back to 375. Dredge half the fish in batter with a fork and gently drag across the oil before dropping. Cook for approximately 6-7 minutes. Stirring gently. Turn heat down if it’s browning too fast. Remove fish pieces and place on cooling rack over sheet pan. Cook remaining fish the same way.

Return heat to 375 and add all the potatoes. Stirring, cook another 2 minutes or until crispy and browned thoroughly. Remove from oil and sprinkle with salt. Serve with fish and tartar sauce.