Beat together the ricotta, milk and egg yolks in a large bowl. Sift together the flour and baking powder in a separate bowl, then fold into the ricotta mixture.
Whisk the egg whites in a clean bowl until they form stiff peaks, then fold into the ricotta mixture with the chives, olives, Gruyère and Parmesan.
Heat a little of the butter in a nonstick frying pan, add spoonfuls of the mixture and fry for 1–2 minutes on each side. Transfer to a serving plate and keep warm while frying the remainder of the mixture, adding the remaining butter to the pan as necessary.
Serve warm with crispy grilled bacon and halved cherry tomatoes, if liked.