Preheat the oven to 200°C.
Place the whole peppers and aubergines into a roasting dish and drizzle over a little oil then season with salt and pepper. Roast in the preheated oven for 25 minutes, then add the cherry tomatoes and roast for a further 20 minutes, or until the skins of the peppers and aubergines are slightly charred (the aubergines may need a little longer than the peppers).
Once roasted allow to cool completely, then peel the aubergines and peppers and pull them apart into strips of flesh. Meanwhile caramelise the onion. Heat a little oil in a frying pan over a medium heat. Add the finely sliced onion and allow to slowly cook down for about 10 minutes or until softened. Add the sugar and vinegar and cook for a further 10 minutes, stirring occasionally, until the onions are dark, sticky and sweet. Allow to cool.
Place the couscous into a heatproof bowl and crumble in the stock cube along with a little salt and pepper. Give it a good mix together, then pour over some hot water so that it covers the couscous by about 2cm. Cover with cling and allow to soak for a few minutes, until the couscous has swollen and the water is all absorbed. Once cool, add the strips of pepper and aubergine, the roasted tomatoes, caramelised onions, spice mix, chilli and coriander as well as a good pinch of salt and pepper.
Give it a good mix, then crumble in the goats cheese and mix through gently. Make sure you taste it to ensure the seasoning is just right.
For the pastry, place the clean table cloth onto the counter top. Line up 5 sheets of filo pastry, top to bottom, overlapping each one over the previous one by a good 2 inches. Repeat with the other 5 starting from the same point, overlapping over the previous 5 by 2 inches.
So you should end up with a panel of filo sheets, 2 wide, 5 deep. Paint the butter over the filo with a pastry brush. Pile the filling into a line across the pastry – make sure you pile it at the first two sheets of filo, and leave a good 2 inches either side of the filling. Using the tablecloth, roll the filling up into the pastry and tuck the excess bits of pastry under the strudel.
Arrange on a large baking sheet – you may need to snake the strudel around – then bake in the preheated oven for 50 – 60 minutes, or until the pastry is a deep golden brown.
For the salad, simply mix all of the ingredients together and serve.