In a large pot of salted, boiling water, place bell peppers and cook for five minutes, turning peppers so all sides are submerged throughout the cooking process; set aside and let cool.
While the peppers are cooling, in a small mixing bowl, add quinoa, cucumber, pickled onion, greek yogurt, and olive oil; stir.
Slice peppers down the middle, from top to bottom, remove the piths and seeds, and dry them out with a paper towel.
Spoon quinoa mix into the hollows of each pepper, drizzle with olive oil and lemon juice, season with oregano, salt, and pepper and serve with a sprinkle of feta on top!
