Cook the quinoa by adding the quinoa into a medium pot along with 1.5 cups water. Bring to a low boil, reduce heat to medium-low, cover with lid, and cook for 13-17 minutes until the water is absorbed and the quinoa is fluffy. Remove from heat, fluff with a fork, and leave the lid on to keep warm.
While cooking your quinoa, preheat oven to 400F and line one extra-large (or 2 large) baking sheets with parchment paper.
Toss the green beans and carrots with the coconut oil and season with salt and pepper. Spread into an even layer onto the baking sheet.
Roast for 15 minutes, remove from the oven and flip, and continue roasting about 10 more minutes.
During the roasting period, chop the spinach and celery.
When the vegetables are finished roasting, spoon the beans and carrots into a large serving bowl.
Stir in the quinoa and the other chopped vegetables.
Drizzle with tamari, squeeze the fresh lemon on top and season with more salt and pepper as needed, to your taste. Serve immediately. Leftovers can be eaten reheated or at room temperature over a salad for a few days.