Jon's Childhood Treat

Vegetable oil, for deep-frying

1 cup all purpose flour
1 cup brown beer
1 1/2 pounds cod fillets
8 russet potatoes, peeled, cut lengthwise into 1/2-inch-thick slices, then cut lengthwise into 1/2-inch-wide strips

Heat oil over high heat until thermometer registers 360°F. Meanwhile, whisk flour and beer in medium bowl until smooth batter forms. Sprinkle fish with salt and pepper. Add fish to batter and stir to coat. Add potato to deep fryer; fry until golden brown and crisp, stirring often, about 7 minutes. Transfer potato to paper towels. Sprinkle with lemon and lime salt and malt vinegar. Add fish to fryer; fry until coating is golden and crisp and fish is just opaque in center, about 3 minutes per side. Transfer fish to paper towels. Sprinkle with lemon and lime salt and malt vinegar.