Heat the oven to 375°F. Lightly grease 8 cups of a standard muffin pan.
In a large bowl, combine the ground turkey, cooked quinoa, egg, feta, red onion, oregano, garlic powder, salt, and black pepper. Mix gently until the ingredients are evenly combined.
Divide the mixture among the prepared muffin cups, pressing it in lightly. Bake for 22 to 25 minutes, until the muffins are cooked through.
While the muffins bake, combine the cucumber, cherry tomatoes, parsley, olive oil, and lemon juice in a bowl. Toss gently and set aside.
Let the muffins rest in the pan for a few minutes, then serve them warm with the cucumber salad.