Couscous with vegetables

I like couscous from marks&spencer and have tried to recreate using the ingredients on its label and come to the conclusion that it needs more olive oil and sugar than what I  would normally put. Neverthe less, this recipe is easy and tasty.
Ingredients:

1 1/2 cups slivered yellow onion
2 cloves garlic, minced
1 tablespoon olive oil
1 cup sliced carrots
1 cup peeled, cubed sweet potato
1/4 teaspoons ground turmeric
2 teaspoons ground cumin
1/2 teaspoon salt
3/4 cup water

1 cup sliced zucchini
1 cup green sweet pepper, chopped
3/4 cup cherry tomatoes, quartered
10 oz couscous

Method:

 1. cook onion and garlic in hot oil over medium heat until tender. Add all the veggies except tomato, spices and salt. Saute.

2.Add water. Bring to boil and reduce heat. Cook, covered, for 5 minutes until tender. Stir in tomatoes.
3. Meanwhile, prepare couscous with veg stock cube and boiled  water (1:2,usually) , according to package instructions.
4. Transfer couscous to large bowl. Add vegetable mixture, stir gently.
Serve immediately.