Preheat your oven to 350°F (175°C) and lightly grease six wells of a standard muffin tin.
Heat the olive oil in a small skillet over medium heat and sauté the ground turkey and diced red bell pepper until the turkey is fully browned.
Add the baby spinach to the skillet and stir for 1 minute until just wilted, then remove from heat.
In a mixing bowl, whisk together the egg whites, whole egg, sea salt, black pepper, garlic powder, and dried oregano until the mixture is frothy.
Divide the cooked turkey and vegetable mixture evenly among the six prepared muffin cups.
Pour the egg mixture over the turkey and vegetables, filling each cup about three-quarters of the way to the top.
Sprinkle the crumbled feta cheese over each cup for a salty finish.
Bake for 20 to 25 minutes until the egg bites are set in the center and the tops are slightly golden.