Preheat the oven to 400°F (200°C).
Rinse the quinoa in a fine mesh strainer and place it in a medium saucepan with 2 cups of water. Bring to a boil, then reduce the heat to low and simmer for 15-20 minutes, or until the water is absorbed and the quinoa is tender. Fluff with a fork and set aside.
In a large bowl, toss the sliced bell peppers, zucchini, and red onion with 2 tablespoons of olive oil. Season with salt and pepper to taste.
Spread the vegetables out in a single layer on a baking sheet and roast for 20-25 minutes, or until tender and lightly browned.
In a small bowl, whisk together the lemon juice, 1/4 cup of olive oil, minced garlic, and salt and pepper to taste.
In a large bowl, combine the cooked quinoa, roasted vegetables, chopped parsley, mint, and basil. Pour the lemon dressing over the top and toss to combine.
Serve the quinoa and roasted vegetable salad warm or at room temperature. Enjoy!