Preheat your oven to 400°F (200°C).

Rinse quinoa under cold water in a fine-mesh sieve.

In a medium saucepan, combine the rinsed quinoa and 2 cups of water (or vegetable broth). Bring to a boil, then reduce heat to low, cover, and let simmer for about 15 minutes, or until quinoa has absorbed all the liquid.

While the quinoa is cooking, prepare your roasted vegetables by tossing diced bell pepper, zucchini, halved cherry tomatoes, and diced red onion with olive oil. Season with salt and pepper to taste.

Spread the seasoned vegetables onto a baking sheet in a single layer. Roast in the preheated oven for about 20 minutes, stirring halfway through, until vegetables are tender and lightly charred.

Once the quinoa is cooked and the vegetables are roasted, fluff the quinoa with a fork and transfer it to a large serving bowl. Mix in the roasted vegetables gently until evenly combined.

Garnish with freshly chopped parsley before serving.