Ingredients

• Vegetable oil (for deep-frying)
• 1/2 cup all purpose flour
• 1/2 cup water
• 3/4 pound orange roughy or cod fillets (about 3/4 inch thick), cut crosswise into 1 1/2-inch-wide strips
• 1 1-pound russet potato, peeled, cut lengthwise into 1/2-inch-thick slices, then cut lengthwise into 1/2-inch-wide strips
• Malt vinegar or apple cider vinegar

Instructions

1. Pour enough oil into heavy large skillet to reach depth of 1/2 inch. Heat oil over high heat until thermometer registers 360°F.
2. Meanwhile, whisk flour and 1/2 cup water in medium bowl until smooth batter forms. Sprinkle fish with salt and pepper. Add fish to batter and stir to coat. Add potato to skillet; fry until golden brown and crisp, stirring often, about 7 minutes. Using tongs, transfer potato to paper towels. Sprinkle with salt and pepper.
3. Add fish to skillet; 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 salt and pepper. Serve with vinegar.