Start by rinsing the quinoa under cold water and then cooking it according to package instructions. This usually takes around 15 minutes.
In a medium-sized mixing bowl, combine the black beans, chopped red bell pepper, and onion. Toss them together.
To the mixture, add the cooked quinoa, cumin powder, salt, and black pepper. Mix well.
On a flat surface, lay out a tortilla.
Spread half of the quinoa and black bean mixture evenly onto half of the tortilla.
Sprinkle with half the cheese.
Add a generous layer of spinach leaves.
Fold the tortilla over.
Heat up a pan over medium flame and drizzle it with olive oil.
Place the prepared quesadilla on the pan.
Cook each side for about 2-3 minutes, or until it turns golden brown.
Once cooked, transfer to a cutting board and let it cool slightly.
Using a sharp knife, slice the High Protein Vegetarian Quesadilla into halves or quarters, as desired.
Serve with sliced avocado and a dollop of Greek yogurt on the side.