In a pot, bring the water and butter to a boil. Season with salt. Remove from the heat and add the couscous. Cover and let stand for 5 minutes. Fluff with a fork. Transfer to a salad bowl and set aside.
In a skillet over medium-low heat, heat the oil. Add the cherry tomatoes and cook for 5 minutes, stirring frequently, until the tomatoes just begin to burst. Deglaze with the vinegar. Season with salt and pepper. Pour over the couscous and mix gently. Refrigerate for 30 minutes.
Add the remaining ingredients to the salad bowl and stir gently to combine. Adjust the seasoning.
Serve as a side dish for grilled fish or meats. Perfect for picnics.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.