Preheat the oven to 400 degrees F. Prepare the quinoa according to package instructions.

Spread the onion, zucchini, yellow squash, and green beans on a large baking sheet and drizzle with 1 tablespoon of grapeseed (or olive) oil, and sprinkle with sea salt. Use your hands to toss everything together until well-coated. Wrap the cloves of garlic in foil and place the garlic and the sheet of veggies in the oven. Roast for 20 to 25 minutes, or until veggies are golden-brown and tender. Once cool enough to handle, unwrap and peel the garlic.

Add the cooked quinoa and roasted vegetables to a large serving bowl. Finely chop the roasted garlic and add it to the serving bowl along with the zest and juice of 1 lemon (about 3 tablespoons of lemon juice). Add the remaining tablespoon of oil, sea salt and walnuts and toss everything together until well combined. Taste the salad for flavor and add more sea salt and/or lemon juice to taste.