What kinds of veg do you roast? I often roast my broccoli, for example, rather than steam it as I used to. You just take a small roasting tray, chop a head of broccoli into smallish pieces, stem and all, drizzle the tray with olive oil, also the broccoli, turn it over until it's all coated, and sprinkle with chopped garlic. Roast for 25 minutes, turning once during that time. It's a different vegetable done that way.
Also I roast masses of veg all at once. I prepare a mixture of potatoes, sweet potatoes, butternut squash, carrots, quartered onions, sometimes parsnips, maybe some big chunks of peppers, chunks of leek, perhaps courgettes and pumpkin. Again, coat with olive oil and sprinkle with garlic. Serve with the roast, but any leftovers can be added to couscous along with any left over broccoli.
Couscous is so simple, just add one and a half times water to the amount of grains, add a little olive oil, any spices that you like (I use a moroccan mix) a lot of lemon juice, salt, pepper, a handful of sultanas and your roasted leftover veg, chopped much smaller. You can keep it in the fridge all week and use it as a base for meals, adding a selection of things like feta cheese, chopped chicken, sausage chunks, chorizo, olives. You can add dressings to it, mix it into a green salad, add chopped fresh herbs. It's very versatile. I always have a bowl of it in the fridge and a bag in the freezer, so that if someone turns up unexpectedly for lunch it looks as if I have spent hours cooking. Which I most certainly have not.