Heat oven to 200C/fan 180C/gas 6. Peel the potatoes and cut them into long chip shapes – the thickness you do is entirely up to you, though the width of your finger is ideal. Rinse under the cold tap and pat dry with a tea towel.
Spread the chips on a large non-stick baking tray and toss with oil and celery
salt. Lie them fl at in a single layer – use two trays rather than overcrowd one.
Roast for 45-50 mins, turning now and then. When cooked they should be
golden brown and crisp with a light fluffy centre. Scatter on sea salt to serve.