Preheat oven to 350 degrees. Toast pine nuts for four minutes.
Combine cooked quinoa, red pepper, red onion, black beans (if using) and parsley.
In a small bowl combine minced garlic, lemon juice, lemon zest, salt, pepper and red pepper. Stir in olive oil. Toss dressing with quinoa mixture. Top with feta cheese. Serve at room temperature or chilled.