- In soup pot, heat oil over medium heat.
- Add onions and cook, stirring until softened, about 5 minutes.
- Add potatoes, squash, carrots, tomatoes and barely enough water to cover.
- Bring to a simmer, then add cumin and turmeric and simmer gently, covered, until vegetables are tender, about 25 minutes.
- Add chickpeas and season to taste with salt and pepper. Simmer over low heat another 5 minutes.
- Meanwhile, put couscous into an ovenproof bowl and cover with 2 cups boiling water.
- Cover bowl and let stand 5 to 10 minutes, then fluff couscous with fork.