Rinse the quinoa thoroughly under cold water using a fine mesh strainer.

In a medium saucepan, combine the quinoa and vegetable broth (or water). Bring to a boil over medium-high heat, then reduce the heat to low, cover, and simmer for 15 minutes, or until the quinoa is cooked and the liquid is absorbed. Remove from heat and set aside.

Heat the olive oil in a large skillet over medium heat. Add the diced onion and sauté for 3-4 minutes, until softened.

Add the minced garlic and diced bell pepper to the skillet. Cook for another 2-3 minutes, stirring often, until the vegetables are fragrant and slightly softened.

Stir in the cooked quinoa, black beans, diced tomatoes (with juices), chili powder, ground cumin, smoked paprika, salt, and black pepper. Mix everything well and let it cook for 5 minutes, allowing the flavors to meld together.

Reduce the heat to low and sprinkle the shredded cheddar cheese evenly over the quinoa mixture. Cover the skillet and let the cheese melt, about 2-3 minutes.

Remove the skillet from heat and sprinkle with fresh cilantro, if desired. Serve warm, topped with sliced avocado and tortilla chips on the side if preferred.