Preheat oven to 425. Separate onions into individual strips after slicing. Toss onions and tomatoes with olive oil, sprinkle with salt and pepper, and spread on a baking sheet. Roast until onions are beginning to get crispy and tomatoes have burst and are juicy, 15-20 minutes.
In the meantime, add quinoa to a pot with 1 1/2 cups water. Bring to a boil and simmer until tender, about 12-15 minutes. Drain excess water.
While quinoa and vegetables are cooking, prepare the dressing by blending all ingredients together.
Once quinoa and vegetables are ready, stir them together with half of the dressing. Serve on a bed of arugula with extra dressing alongside. You may have leftover dressing.
Enjoy!
Recipe by Coffee & Quinoa at https://www.coffeeandquinoa.com/2013/05/warm-quinoa-and-arugula-salad-with-lemon-dressing/