Stuffed Onions with sun-dried tomato & hazelnuts

With skins on, chop the top centimetre or so from each onion and wrap each one in foil. Bake at 180°C for one hour. Unwrap and leave to cool. (This stage can be done a day in advance if you have time).
Put the hazelnuts on a baking tray onto the bottom shelf and roast for 5 minutes until starting to brown and skins become loose.
Bring the vegetable stock to the boil in a saucepan, then add the giant cous-cous and simmer for 6-8 minutes until just cooked through. Drain and set aside to cool.
Finely chop the roasted hazelnuts, sun-dried tomatoes and vegan feta. Tip them into a large bowl.
Add the giant cous cous to the bowl, then sprinkle over the chilli flakes, sultanas and fresh mint, and mix gently to combine but without breaking up the feta too much.
Taste the cous cous mixture, then season with salt and black pepper as required.
Remove the skins from the roasted onions - they should peel off fairly easily. Gently pull/scoop out the centre of each onion, leaving just two layers in tact to stuff, (a sharp knife and teaspoon are handy for this job). Place the empty onions back on the baking tray to stuff.
Take the discarded onion insides, chop finely and add one third to the stuffing mixture. (Keep the rest in the fridge to add to pasta sauces, curries, chillis etc!).
Carefully fill each onion with stuffing mixture, pressing down to ensure they are packed full. Scatter over the grated vegan cheese (if you wish), and bake for 15 minutes until bubbling and browning on top.