Mix the balsamic vinegar, water and ProCrema in a saucepan. Add the sugar and heat until gently dissolved

Cool and then place into a gas canister. Fill the canister with 2 charges and refrigerate until needed

Preheat a deep-fat fryer of vegetable oil to 170°C or use a large pan. Peel the potatoes and thinly slice, drying well before frying

Deep fry the potato slices until light brown and crisp. Depending on the size of your fryer, you may have to do this in batches. Sprinkle the crisps with sea salt

Take the gas canister from the fridge and decant the foam into a small serving dish. Serve alongside the crisps