1

To make the batter, mix the flour, 1 teaspoon of salt, and the baking powder with the water. Keep cold and use within 20 minutes of making.

2

Preheat the oven to 300°F (150°C). Line a baking sheet with plenty of paper towels and set aside.

3

Peel the potatoes and cut them lengthwise into fries 1/2 inch (1 cm) thick. Pour some oil into a large, deep pan until it is about one-third full and heat it to 260°F (l30°C). Drop half the fries into a frying basket and cook them for about 5 minutes, until tender when pierced with the tip of a knife but not colored. Lift them out and drain off the excess oil. Repeat with the rest of the fries, then set aside.

4

To fry the fish, heat the oil to 325°F (160°C). Season the cod fillets with salt and pepper, then dip into the batter. Fry, two pieces at a time, for 7 to 8 minutes, until crisp and golden brown. Lift out and drain on the paper-lined baking sheet. Keep hot in the oven while you cook the other two pieces of fish.

5

Raise the temperature of the oil to 375°F (190°C). Cook the fries in small batches for about 2 minutes, until crisp and golden. Lift them out of the pan and shake to remove the excess oil, then drain on paper towels. Sprinkle with salt. Serve the cod and fries with the tartar sauce.