Spray four 1-cup ramekins with cooking spray; put aside. Heat the oil in a medium nonstick frying pan over moderate heat. Add the spring onions and garlic and cook for 1 minute. Stir in the broccoli and cook for 1 minute.
Process the cottage cheese in a food processor until smooth. Add the milk, whole eggs, egg whites, flour and a pinch of pepper, and process until well combined. Transfer the custard to a large bowl. Add the broccoli mixture and crumble in the feta cheese, stirring to combine.
Spoon into the prepared ramekins, place on a baking tray, then bake for 30 minutes or until the quiches are puffy and set.