Preheat your oven to 180°C.

Cut the top off the red bell pepper and remove the seeds and membranes.

In a skillet over medium heat, add a drizzle of oil and sauté the onion until translucent.

Add the ground beef to the skillet, breaking it into small pieces, and cook until browned.

Stir in the spinach and cook until wilted.

Mix in the cooked quinoa, oregano, garlic powder, and season generously with salt and pepper.

Fill the hollowed-out bell pepper with the beef mixture, pressing down to pack it tightly.

Place the stuffed pepper in an oven-safe dish and top with crumbled feta cheese.

Bake in the oven for 25-30 minutes or until the pepper is tender and the top is slightly browned.