I was inspired by Canelle et Vanille for this recipe, which is one of the most beautiful blog I visited so far, please have a look, her pictures are simply stunning. Her recipe gives you the gluten free option, mine gives you a faster and cheaper way to make the pastry.

Ingredients
-For the pastry:

• 125g slightly salted butter
• 1 egg yolk
• 125g rye flour
• 125g plain flour
• A pinch of salt
• 50ml of water

-For the filling:

• 250g of normal beetroots
• 250g of golden beetroots
• 250g of candy beetroots
• 7 little pearl onions
• 1 big fennel, washed
• Half a golden onion
• Half a red onion
• 2 tbsp of vegetable oil
• 4 tbsp of balsamic vinegar
• 100g grated emmental

Switch the oven in at 200C. Wash the beetroots carefully so you don’t pierce the skin, do not cut the roots yet and chop the leaves off by leaving at least 5cm of stalks. You will chop them off later, but right now you want to make sure their beautiful colour don’t leak out. Wrap them individually in foil and cook in the oven for 40 minutes or until soft when you insert a knife.
Meanwhile make your pastry. Mix the flours and the butter together until you get crumbs and then add the egg, salt and water to form a compact ball. Wrap in cling film and leave in the fridge for 1h.
Chop the fennel and the onions finely and fry them in the oil over a medium heat. When they start to soften, add the balsamic vinegar and mix well. Cook for an extra 5 minutes to caramelised slightly. Set aside to cool.
When the beetroots are ready, turn the oven down to 180C. Cut away the roots and stalks and peel the beets. Cut them in half and position them face down in a cake tin. Arrange them the way you want around the tin. Spare beets can be chopped to fill gaps, but here I’ve used pearl onions.
Pour the caramelised fennel on the beets and add the grated cheese on top.
Take the pastry out and roll it to roughly the size of the tin then place it on top of the cheese, tucking under the edges. Cook for 30 minutes until the pastry is cooked. Leave the tart inside the tin until you can handle the tin without burning your hand then place a plate on top of the tart and flip it over. There might be some beetroot pieces still stuck inside, just unstick them and position them back where they belong on the tart.