Place the couscous in a bowl, measure out 1 1/3 cups of water, place in a saucepan and add 3 Tablespoons olive oil, the clove of garlic, thyme and stock cube, season with salt. As soon as it boils, pour over the couscous, mix well and cover in cling film. Leave to steam for 20 minutes.
Place the peppers, zucchini, eggplant and asparagus in a large bowl, season, add 3 tablespoons of olive oil and cook on a hot griddle (do not pile them on top of each other, if they don’t all fit cook in batches). Cook for 8-10 minutes, moving them occasionally. Once all the vegetables are cooked, place them back in the bowl. Add the red wine vinegar and chopped spring onion.
Take the cling film off the bowl of couscous, pick out the garlic and thyme and fluff up using a fork. Once all the grains are separated, add to the vegetables. Add the rocket, check the seasoning and serve up.