Preheat your oven to 350°F. Rinse and chop one head of cauliflower into small florets, or use frozen. Thinly slice the onion and garlic.
Spread the cauliflower florets and onion slices on a baking sheet and drizzle with 1 tablespoon of olive oil, Italian seasoning, paprika, and a sprinkle of salt and pepper and toss to coat. Roast the cauliflower in the preheated oven for 25-30 minutes, until they are golden brown and tender.
While the cauliflower and onion are cooking, cook 1 cup of quinoa according to package instructions, using the vegetable stock instead of water. Once the quinoa is ready, set it aside to cool. You can use the same pan you cooked the quinoa in to cook the peas and garlic. Season with salt, pepper, and garlic powder and cook through, about 5 minutes if using canned or frozen.
In a large bowl or serving platter, add the kale and/or spinach. If using kale, drizzle with a tiny bit more olive oil and a pinch of salt, and massage the kale to soften it. Add the roasted cauliflower, peas and cooked quinoa on top of the greens.
Add the lemon juice to the bowl, salt and pepper to taste, and toss. Drizzle generously with balsamic vinegar.
(Optional) Add 1/4 cup chopped fresh herbs, such as parsley, basil or cilantro, or 1/4 cup chopped nuts, such as almonds or walnuts, for added texture and flavor.