With rich, sweet caramelized onions nestling inside a crisp cheesy and herby wholemeal pastry crust, this vegan onion tarte tatin makes for a great summertime lunch or supper, and is perfect for picnics too!
Place a sturdy baking sheet (or roasting pan) into your oven, and pre-heat to 180°C (350°F, gas mark 4).
Peel and top & tail the onions, then cut them in half widthways (i.e. perpendicular to the root and stalk ends)
Place a shallow non-stick ovenproof pan (e.g. a 25cm/10" cast iron skillet) over a medium heat, and add the oil and the palm sugar. Once it starts to sizzle, add the sprigs of savory.
Place the onions, cut side down, into the pan, and arrange them so they all fit in, and season with the salt and pepper.
Drizzle in the balsamic vinegar, and then sprinkle the savory leaves over the top.
Reduce the heat (using a heat diffuser if necessary), and gently cook the onions for 10 mins.
Cover the pan with a lid or some tinfoil, and then place onto the baking sheet, and bake in the centre of the oven for 40 mins. Test by sticking a skewer into the onions - they should be soft but still have some texture. If they're not quite ready, give them another 5 mins or so.
Once the onions are cooked, remove the pan from the oven (leaving the baking sheet inside), and place on the hob over a medium heat for 10 mins or so, until the juices have reduced, and you're left with sticky onions in a small amount of syrup.
Raise the oven temperature to 200°C (400°F, gas mark 6).
Make the pastry:
While the onions are in the oven, make the pastry by rubbing together the flours with the butter until you have what looks like breadcrumbs.
Mix in the nutritional yeast and vegan Cheddar (if using), and savory leaves, and then bind it together with 2-3 tablespoon of cold water, to make a soft dough. Wrap, and place in the 'fridge for 30 minutes to rest.
Putting it all together:
While the onions are reducing, roll out the pastry into 25cm (10") circle.
Once the juices have reduced, turn off the heat under the pan, and carefully place the pastry over the top of the onions, making sure you tuck the edges down around them. Please don't burn yourself!
Place the tarte onto the baking sheet in the centre of the oven, and bake for around 25 mins, until the pastry is crisp, and has turned a deeper-brown.
Remove from the oven, and set aside to cool for 15 mins.
Place a chopping board or large plate over the pan, and flip the whole thing over. Do wear oven gloves!
Give the pan a bit of a shake to loosen its contents, and the tarte should come away cleanly. Any onions which have been left behind can be gently lifted with a flexible spatula, and placed into their respective gaps.