Rinse the quinoa under cold water in a fine mesh strainer to remove any bitterness.
In a medium saucepan, combine the rinsed quinoa and vegetable broth. Bring to a boil over medium heat.
Once it reaches a boil, reduce the heat to low, cover, and let it simmer for about 15 minutes or until the quinoa is fluffy and the liquid is absorbed.
While the quinoa is cooking, heat olive oil in a skillet over medium heat. Add the chopped onion and sauté for 3-4 minutes until translucent.
Add the minced garlic and diced bell pepper to the skillet. Cook for an additional 3-4 minutes until the peppers are tender.
Stir in the chopped spinach and cook until wilted, around 2 minutes.
Once the quinoa is ready, fluff it with a fork and combine it with the sautéed vegetables in the skillet. Add salt, black pepper, and ½ of the shredded cheese.
Mix well until the cheese is melted and evenly distributed.
Serve the cheesy quinoa warm, topped with the remaining shredded cheese and garnished with fresh parsley if desired.