Combine couscous, bouillon cubes and 3 cups of water in a saucepan. Bring to a boil and cook until tender, about 10 minutes. Drain, reserving a few tablespoons of the liquid.
Combine all of the dressing ingredients with 2 tablespoons of the reserved cooking liquid. Whisk well until thoroughly combined.
Add to couscous, with carrots and scallions. Add dressing and toss until well combined. Add peanuts and toss until thoroughly incorporated.
Serve chilled or at room temperature.