Tomatoes and Dressing
2 pints (1 1/2 pounds) grape or cherry tomatoes (1 1/2 lb)
3 large garlic cloves, left unpeeled
1/4 cup olive oil, plus more for tomatoes
1/4 cup warm water
1 teaspoon fresh lemon juice
1 teaspoon kosher salt
1/4 teaspoon black pepper
Couscous
2 3/4 cups vegetable broth
2 1/4 cups (12 ounces or 340 grams) pearl couscous, sometimes sold as Israeli couscous
1/2 cup Kalamata or other brine-cured black olives, pitted and chopped
1/3 cup chopped fresh flat-leaf parsley
1/4 cup chopped fresh mint
1 teaspoon chopped fresh thyme
Prepare tomatoes:
Heat oven to 300°F. Halve tomatoes through stem ends and arrange, cut sides up, in 1 layer on a large baking sheet. Add garlic to pan and drizzle both tomatoes and garlic lightly with oil (about 1 tablespoon). Sprinkle with salt. Roast in middle of oven until tomatoes are slightly shriveled around edges, about 1 hour. Cool in pan on a rack 20 to 30 minutes.
Meanwhile, make couscous:
Bring broth to a boil in a 3-quart heavy saucepan and stir in couscous, then simmer, uncovered, 6 minutes. Cover pan and remove from heat. Let stand 10 minutes. Spread couscous in one layer on a baking sheet or plate and cool 15 minutes.
When tomatoes are done, make dressing: Peel garlic and puree with 1/4 cup oil, water, lemon juice, 1 teaspoon salt, 1/4 pepper, and 1/2 cup roasted tomatoes in a blender until dressing is very smooth. Adjust seasonings to taste.
Assemble and serve:
Transfer cooled couscous to a bowl and stir in olives, roasted tomatoes, herbs, and dressing. Season to taste with more salt and pepper as needed.
Do ahead:
Roasted tomatoes, dressing, and couscous can be made 1 day ahead and kept separately, covered and chilled. Bring to room temperature before proceeding.