These are a delicious option for lunch or morning or afternoon tea. The sweetness of the beetroot is enhanced with roasting with a bit of honey in addition to the sticky onion jam and is balanced by the salty feta and the savoury walnuts . This recipe makes 8 tarts which are fairly large , each being a quarter of a sheet of puff pastry.
The addition of steam to the roasting and the pastry cooking avoids the beetroot drying out and also creates a puffier pastry, but if you dont have a steam or steam assist oven you will still get a delicious result with a regular dry oven .

If you are short on time you can use a pre purchased onion jam.

Peel and dice the beetroot and toss in bowl with Olive Oil, fennel seeds, honey and salt and pepper.
Preheat oven to Hot Air, 200C  60% humidity or similar, and roast beetroot for 20 – 30 minutes or until tender.
While beetroot is cooking prepare onion jam by slicing onions.
Heat oil in frying pan and gently fry onions being careful not to let them go too brown.
Add sugar, balsamic, fennel and mustard seeds and star anise and gently simmer for 30 minutes or until onions are caramelised and sauce is reduced to a sticky sweet glaze. Remove star anise before use.

Prepare pastry by dividing each sheet into 4 squares.
Mark a border of 1cm around the edge of each square with the back of a knife and dock the centre by pressing a fork repeatedly into the pastry.

Spread the centre of each square with onion jam, and then pile on beetroot. Crumble over feta cheese and broken walnut pieces.

Preheat oven fan assisted or top and bottom + steam 220C 50% humidity. Place tarts near the bottom of the oven, and cook pastries for 15-20 minutes or until pastry is puffed and golden and feta is lightly browned.

If required add 10 minutes bottom heat only 180c to firm up pastry base.