To make dressing, cut each tomato into eighths. Toss tomatoes and unpeeled garlic cloves with 1⁄8 cup of the oil.
Place tomatoes skin-side down on a baking pan. Add garlic cloves to pan. Roast until tomatoes start to shrivel around their edges, approximately 1 hour. Remove from oven and allow to cool for 20 minutes.
Peel garlic cloves. Add garlic, tomatoes, vinegar, remaining 1⁄8 cup of oil, and salt and pepper to taste in a blender. Puree until smooth.
In a large bowl, mix together cooked quinoa, olives, pine nuts, 1 1⁄2 cups of the Roasted-Tomato Dressing, and salt and pepper to taste. Garnish with chopped mint.
Notes
Serve the quinoa with extra dressing on the side, if desired. The dressing is also delicious over salads or steamed vegetables, or as a dip for crusty bread.