Preheat your oven to 425°F (220°C) and prepare a baking sheet lined with parchment paper.
In a large bowl, toss zucchini, red bell peppers, yellow bell peppers, cherry tomatoes, and red onion with olive oil, dried Italian herbs, salt, and black pepper. Spread on the prepared baking sheet.
Roast the vegetables in the oven for 20–25 minutes, stirring halfway through for even cooking.
While the vegetables are roasting, bring salted water to a boil and cook the orzo until al dente, about 8-10 minutes. Drain and set aside.
In a large bowl, mix the cooked orzo with roasted vegetables, lemon juice, and chopped parsley.
Sprinkle optional cheese on top and adjust seasoning to taste before serving.