Preheat your oven to 425°F (220°C).
Toss the diced zucchini, chopped bell peppers, halved cherry tomatoes, and sliced red onion in a bowl with olive oil, dried herbs, salt, and black pepper until well-coated. Spread them evenly on a lined baking sheet.
Place the baking sheet in your preheated oven and roast the vegetables for about 20–25 minutes. Stir them halfway through roasting to ensure they caramelize evenly.
While your vegetables are roasting, bring salted water to a boil in another pot. Add the dry orzo pasta and cook according to package instructions until al dente; then drain it well.
In a large mixing bowl, combine the cooked orzo along with the roasted vegetables once they are done baking. Drizzle lemon juice over the mixture followed by fresh parsley; toss gently until everything is well mixed.
If you choose to add crumbled feta cheese or grated parmesan at this point, do so according to taste preferences before serving either warm or chilled!