Line a baking tray with paper towel and place a wire rack on top.
Thinly slice vegetables. Wearing gloves, slice the beetroot last to prevent staining.
Pour oil into a large, deep saucepan. Place over medium-high heat. Once hot, carefully lower vegetables, except beetroot, in batches, into the oil. Cook each batch for about 5 minutes or until golden. Remove with a slotted spoon, allowing excess oil to drip off, and place onto a wire rack. Cook beetroot last to prevent discolouring the oil and the other vegetables. Sprinkle with sea salt flakes and leave to cool.
Once cool, serve chips with dip or store in an airtight container for 2 days if not serving immediately.