Fish and Chips

Whisk flour, cornstarch, 1 1/2 teaspoons salt, and baking powder together in large bowl. Add beer and whisk until smooth. Cover with plastic wrap and refrigerate for at least 20 minutes.

Cut cod crosswise into 8 equal fillets (about 4 ounces each). Pat cod dry with paper towels and season with salt and pepper; refrigerate until ready to use.

Square off each potato by cutting 1/4-inch-thick slice from each of its 4 long sides. Cut potatoes lengthwise into 1/4-inch-thick planks. Stack 3 to 4 planks and cut into 1/4-inch fries. Repeat with remaining planks. (Do not place potatoes in water.)

Line rimmed baking sheet with triple layer of paper towels. Combine potatoes and oil in large Dutch oven. Cook over high heat until oil has reached rolling boil, about 7 minutes. Continue to cook, without stirring, until potatoes are limp but exteriors are beginning to firm, about 15 minutes longer. Using tongs, stir potatoes, gently scraping up any that stick, and continue to cook, stirring occasionally, until just lightly golden brown, about 4 minutes longer (fries will not be fully cooked at this point). Using spider skimmer or slotted spoon, transfer fries to prepared sheet. Skim off any browned bits left in pot.

Set wire rack in second rimmed baking sheet. Transfer fish to batter and toss to evenly coat. Heat oil over medium-high heat to 375 degrees. Using fork, remove 4 pieces of fish from batter, allowing excess batter to drip back into bowl, and add to hot oil, briefly dragging fish along surface of oil to prevent sticking. Adjust burner, if necessary, to maintain oil temperature between 350 and 375 degrees.

Cook fish, stirring gently to prevent pieces from sticking together, until deep golden brown and crispy, about 4 minutes per side. Using spider skimmer or slotted spoon, transfer fish to prepared rack and skim off any browned bits left in pot. Return oil to 375 degrees and repeat with remaining 4 pieces of fish.

Return oil to 375 degrees. Add fries to oil and cook until deep golden brown and crispy, about 1 minute. Using spider skimmer or slotted spoon, transfer fries back to prepared sheet and season with salt. Transfer fish and chips to platter. Serve with lemon wedges.