In a medium saucepan,bring quinoa and water to a boil. Cover, reduce heat to low, and simmer until for 15 minutes, or until quinoa is tender. Remove from heat and let stand for 5 minutes, covered. Remove lid and fluff with a fork. Transfer quinoa to a large bowl.
Add the roasted broccoli, spinach, and green onion to the quinoa. Drizzle with olive oil and fresh lemon juice. Gently stir. Add the chopped pistachios, feta cheese, and season with salt and black pepper, to taste. Serve.