Preheat oven to 375°F. Prepare quinoa according to package directions.
While the quinoa is cooking, cut the tops of the tomatoes off and remove the inner core with a paring knife keeping the whole tomato intact. Dice the inner core of the tomatoes.
Heat Basil Pesto Grapeseed Oil in a 12-inch nonstick skillet over medium heat. Add the onion and sauté for 3-5 minutes or until translucent. Add diced tomato and spinach and sauté until spinach is wilted.
In a large mixing bowl, combine the cooked quinoa, sauteed tomato mixture, and Basil Pesto Sauce.
Fill each tomato with the quinoa mixture. Place the stuffed tomatoes in a baking dish. Top each with cheddar cheese. Bake for 20 minutes. Garnish with basil.
