Steps
Preheat the oven to 375°F (190°C).
Cut the top off the bell pepper and remove the seeds and membranes.
In a bowl, combine the cooked quinoa, cherry tomatoes, cucumber, olives, feta cheese, olive oil, lemon juice, oregano, salt, and pepper. Mix well.
Stuff the bell pepper with the quinoa mixture, pressing down gently to pack it in.
Place the stuffed pepper upright in a baking dish and cover it with foil.
Bake in the preheated oven for 25-30 minutes, until the pepper is tender.
Remove from the oven, let cool slightly, and garnish with fresh parsley before serving.