Why this recipe works: For our fish and chips recipe, we wanted to find a batter that would not only protect the fish as it cooked but would also provide it with a nicely crisp contrast. A wet batter made with beer proved to be the most effective way to coat and protect the fish. What was the best way to keep the coating crisp for our best fish and chips recipe? The answer was a 3:1 ratio of flour to cornstarch, along with a teaspoon of baking powder. A final layer of flour over the battered fish kept the coating in place as the fish fried.

• 3 pounds russet potatoes (about 4 large potatoes), peeled, ends and sides squared off, and cut lengthwise into 1/2 inch by 1/2-inch fries
• 3 quarts peanut oil (or canola oil), plus 1/4 additional cup
• 1 1/2 cups all-purpose flour
• 1/2 cup cornstarch
• 1/2 teaspoon cayenne pepper
• 1/2 teaspoon paprika
• 1/8 teaspoon ground black pepper
• Table salt
• 1 teaspoon baking powder
• 1 1/2 pounds 1-inch-thick cod fillet (or other thick white fish, such as hake or haddock) cut into eight 3-ounce pieces
• 1 1/2 cups beer (12 ounces), cold

• Place cut fries in large microwaveable bowl, toss with 1/4 cup oil, and cover with plastic wrap. Microwave on high power until potatoes are partially translucent and pliable but still offer some resistance when pierced with tip of paring knife, 6 to 8 minutes, tossing them with rubber spatula halfway through cooking time. Carefully pull back plastic wrap from side farthest from you and drain potatoes into large mesh strainer set over sink. Rinse well under cold running water. Spread potatoes onto kitchen towels and pat dry. Let rest until room temperature, at least 10 minutes and up to 1 hour.
• While fries cool, whisk flour, cornstarch, cayenne, paprika, pepper, and 2 teaspoons salt in large mixing bowl; transfer 3/4 cup of mixture to rimmed baking sheet. Add baking powder to bowl and whisk to combine.
• In heavy-bottomed Dutch oven, heat 2 quarts oil over medium heat to 350 degrees. Add fries to hot oil and increase heat to high. Fry, stirring with mesh spider or slotted metal spoon, until potatoes turn light golden and just begin to brown at corners, 6 to 8 minutes. Transfer fries to thick paper bag or paper towels to drain.
• Reduce heat to medium-high, add remaining quart of oil, and heat oil to 375 degrees. Meanwhile, thoroughly dry fish with paper towels and dredge each piece in flour mixture on baking sheet; transfer pieces to wire rack, shaking off excess flour. Add 1 1/4 cups beer to flour mixture in mixing bowl and stir until mixture is just combined (batter will be lumpy). Add remaining beer as needed, 1 tablespoon at a time, whisking after each addition, until batter falls from whisk in thin, steady stream and leaves faint trail across surface of batter. Using tongs, dip 1 piece fish in batter and let excess run off, shaking gently. Place battered fish back onto baking sheet with flour mixture and turn to coat both sides. Repeat with remaining fish, keeping pieces in single layer on baking sheet.
• When oil reaches 375 degrees, increase heat to high and add battered fish to oil with tongs, gently shaking off excess flour. Fry, stirring occasionally, until golden brown, 7 to 8 minutes. Transfer fish to thick paper bag or paper towels to drain. Allow oil to return to 375 degrees.
• Add all fries back to oil and fry until golden brown and crisp, 3 to 5 minutes. Transfer to fresh paper bag or paper towels to drain. Season fries with salt to taste and serve immediately with fish.

• Ask your fishmonger to remove the thin tail portions of the fish.
• For safety, use a Dutch oven with at least a 7-quart capacity.
• Any beer will work in this recipe, even nonalcoholic beer, with the exception of dark stouts and ales.
• Serve with traditional malt vinegar or with tartar sauce.