Finely chop the fresh bell peppers and red onion, rinse the quinoa under cold water, gather black beans, garlic, and spices.

In a medium saucepan, combine rinsed quinoa with 2 cups of water and a pinch of salt and bring to a boil.

Heat olive oil in a large skillet, sauté red onion for 2-3 minutes, then add bell peppers and minced garlic; cook for 5-7 minutes.

Stir in black beans and cooked quinoa with spices; mix well and warm through for 3-4 minutes.

Warm taco shells, fill with quinoa and vegetable mixture, top with avocado slices and salsa.

Serve on a platter and allow others to add their preferred toppings.