Using a mandolin or sharp knife, slice the shallots thinly. In a heavy-based saucepan, heat the vegetable oil to 160°C (315°F). Add the sliced shallots, stirring constantly.
When lightly golden in colour, scoop out the slices with a small sieve, working quickly as they will continue to cook as you scoop. Drain on paper towels. Use a pair of tongs in a side-to-side motion to fluff and separate the slices. This will also help them to cool. Once completely cool, you can store them in an airtight container for up to 4 days.