Preheat oven to 425 degrees F.
Cover 2 baking sheets with aluminum foil. Arrange the diced vegetables on the baking sheets and toss with 2 tablespoons of olive oil; season with salt and pepper.
Roast for 30 minutes or until softened and beginning to brown. Remove from the oven and let cool to room temperature.
Combine the garlic and lemon juice in a large bowl, and slowly add in the remaining 3 tablespoons olive oil, whisking constantly. Season with salt and pepper. Add the tomatoes, basil, mint, quinoa, and roasted vegetables, stirring gently to combine.
Taste and adjust seasoning as needed. Garnish with toasted pine nuts.