- Heat the oven to 180C/160C Fan/Gas 4. Place the pastry into a lightly buttered tart case and prick the base with a fork a few times.
- Slice your onions and fry in a tablespoon of olive oil for about 15 minutes until they begin to caramelise. Add a good pinch of salt.
- Whilst they are cooking, put on your gloves and peel and grate your beetroot. Then place the beetroot into the pastry case. Then cover the beetroot with your onions.
- Whisk your eggs and milk together and season well. Pour over the beetroot and onions and then place in the oven for 15 minutes.
- After 15 minutes, lower the temperature to 160C/140C Fan/Gas 3 and bake for a further 40 minutes until golden.
This recipe is inspired by BBC Good Food