Preheat the oven to 200°C.
Mix flour and sugar, then add in butter until it looks like breadcrumbs.
Add an egg, lemon juice, and some water, and mix to form dough. Let it chill for 15 minutes.
Roll out the dough, line a tart pan, and bake for 15 minutes with baking beans. Remove the beans and bake for 8 more minutes until golden. Trim the edges.
Lower the oven to 180°C (350°F).
Blend beetroot with cream to make a smooth paste.
Whisk some eggs and sugar, then mix it in the beetroot paste, spices, and lemon zest.
Pour the mix into the crust and bake for 30–40 minutes until set. Let it cool completely before serving.