1 lb white, flaky fish (cod, haddock, tilapia)
5 potatoes, washed and scrubbed
1 cup full-flavored beer (such as Dogfish Head 60 Minute IPA)
1 1/4 cup all-purpose flour
2 tbsp + 1 tsp kosher salt
4 cups warm water
Make the soaking mixture for the cut potatoes by combining warm water and 2 tablespoons kosher salt in large bowl. Mix to dissolve salt. Set aside.
To prepare the potatoes, peel the sides of the potato with a vegetable peeler, leaving some skin at the top and bottom. Slice potatoes length-wise, in 1/2″ slices. Then, slice 1/4″ inch strips from those slices. A mandoline or french fry cutter is very handy here! Place cut potatoes in the bowl of salt water and soak for 15 minutes. Remove from water and place the potatoes on a clean kitchen towel to dry for a few minutes. Dry well to avoid splattering when frying.
Fill a dutch oven with vegetable oil, so that oil comes up a little less than halfway up the pot. Place over low heat and heat to 375 degrees. Meanwhile, prepare your beer batter by combining the beer, 1 cup of flour, and a teaspoon of salt in a large bowl. Set aside. Place remainder of flour in a resealable bag and set aside with the beer batter.
Once oil is up to temperature, fry the potatoes in batches, taking care not to overcrowd. Fry until edges are starting to brown, about 3 minutes. Remove to a paper-towel lined cookie sheet. Repeat process with remaining potatoes. Once all potatoes have been fried, bring the oil back up to 375 degrees, and refry them. The “twice-fry” is the key to a crispy french fry. Just another minute or two in the hot oil is all you need. Place them on a cooling rack on a cookie sheet and keep warm in an oven while fish is frying.
To fry the fish, place filets in the bag of flour to lightly coat, then dip into beer batter, and add to the oil. Fry until golden brown, turning fish occasionally, about 6-9 minutes depending on the size of the filets. Remove from oil and drain on paper towel-lined plate for a minute before plating. Serve fried fish over a generous portion of french fries with wedges of lemon for garnish. Tartar sauce and malt vinegar on the side.