In a medium-sized pot, combine the rinsed quinoa with the vegetable broth. Bring to a boil, then reduce heat to a simmer and cover for about 15 minutes.
Prepare the bell peppers by slicing off the tops and removing the seeds and membranes. Stand them upright in a baking dish.
In a large mixing bowl, combine the cooked quinoa, halved cherry tomatoes, halved mozzarella balls, and chopped basil. Drizzle with olive oil and balsamic glaze, and season with salt and pepper. Stir gently.
Spoon the quinoa mixture into each pepper, packing it down gently.
Cover the baking dish with aluminum foil and bake for 25 minutes.
Remove the foil and bake for an additional 10-15 minutes, until the peppers are tender and slightly charred.
Allow the stuffed peppers to cool for a few minutes before serving.
Notes
Arrange the stuffed peppers artfully on a platter and drizzle with extra balsamic glaze for presentation.