Preheat oven to 250c.
Slice the potatoes lengthwise into 3-4 1cm thick slices. Then cut each slice into 2-3 1cm chips.
Bring a large pot of water to the boil. Add the chips, and blanch in the boiling water for 3 minutes. Drain the water, then leave the chips to drain on a teatowel.
Lay them in a single layer on a large roasting tray. Drizzle liberally with olive oil, then sprinkle over chicken salt. Toss to coat.
Bake in the hot oven for 20-25 minutes, or until golden brown and crispy. Turn the chips twice during cooking.
Add at least 5cm of canola oil to a high-sided, heavy saucepan, and heat on the stovetop on a high heat.
Lightly dust the fish fillets in a little flour to coat.
Add the self-raising flour and salt to a bowl. Mix the milk and water together, then gradually beat into the flour. Keep adding in the water/milk mixture until the batter is about piklet batter consistency.
Test how hot your oil is. Add a drop of batter and it should hit the oil and bubble instantly. If the oil begins to smoke, it's too hot, remove from the heat straight away.
Drag fillets through the batter to coat, then fry in the hot oil, 2-3 fillets at a time.
Fry for around 2 minutes, then flip, and fry for another 2 minutes, or until golden and crispy.
Drain the fillets on each side on paper towels as you fry the rest. Pop them onto baking paper in a warming oven, if you have one.
Season the chips with more salt if required. Serve with lemon wedges, and a fresh summer salad of rocket leaves and raw veg. Don't forget the Tom Sauce!