Preheat your oven to 375°F (190°C).
Prepare the zucchinis by slicing them in half lengthwise and scooping out the center.
In a skillet, heat olive oil over medium heat and sauté garlic and bell pepper until soft.
Add cooked quinoa, olives, feta cheese, and oregano to the skillet.
Season the mixture with salt and pepper, adjusting to your taste.
Carefully spoon the filling into each zucchini half, packing them generously.
Arrange the stuffed zucchinis on a baking sheet and cover them with foil.
Bake for 25-30 minutes, removing the foil for the last 5 minutes.
Remove from the oven, cool for a few minutes, and serve warm.
