Gather your ingredients. You'll need quinoa, a variety of vegetables such as bell peppers, zucchini, cherry tomatoes, red onion, and any other vegetables you prefer, olive oil, balsamic vinegar, garlic, salt, pepper, and optional toppings like feta cheese or fresh herbs.
Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper or foil for easy cleanup.
Wash and chop the vegetables into bite-sized pieces. Place them on the prepared baking sheet in a single layer, ensuring they are spread out evenly.
Drizzle the vegetables with olive oil and balsamic vinegar. Add minced garlic, salt, and pepper to taste. Toss the vegetables to coat them evenly with the seasoning.
Roast the vegetables in the preheated oven for about 20-25 minutes, or until they are tender and lightly caramelized, stirring halfway through the cooking time for even roasting.
While the vegetables are roasting, rinse the quinoa under cold water to remove any bitterness. Cook the quinoa according to package instructions, using either water or vegetable broth for added flavor.
Once the vegetables are roasted and the quinoa is cooked, transfer them to a large mixing bowl. Toss gently to combine, being careful not to mash the vegetables or quinoa.
Serve the roasted vegetable quinoa salad warm or at room temperature. Garnish with crumbled feta cheese or chopped fresh herbs like parsley or basil, if desired, for an extra burst of flavor.