Rinse quinoa under cold water.
In a medium saucepan, bring 2 cups of water to a boil. Add quinoa, reduce heat to low, cover, and simmer for 15 minutes or until water is absorbed.
While quinoa cooks, heat olive oil in a skillet over medium heat. Add onion and garlic and sauté for 3-4 minutes until softened.
Add cooked quinoa, black beans, cumin, chili powder, smoked paprika, salt, and pepper to the skillet. Stir well and cook for 5 minutes until heated through and flavors combine.
Warm tortillas in a dry skillet or microwave for a few seconds until soft.
Assemble tacos by spooning quinoa and bean mixture onto tortillas.
Top with shredded lettuce, diced tomatoes, cilantro, cheese, and a dollop of sour cream if using.
Squeeze fresh lime juice over the top and add hot sauce if desired.
Serve immediately and enjoy!