Preheat oven 350 degrees F.

Melt butter and pour it into a single-serving oven-proof custard dish. Add the sour cream and spread it out evenly; distribute the chives evenly over the sour cream. Break the egg into the dish, cantering the yolk.

Place the custard dish in the centre of a pie plate. Sprinkle the cheese on the egg, making a wreath around the yolk. Carefully pour warm water into the pie plate until it reaches half an inch up the side of the custard dish.

Place in the oven and bake for 15-20 min or until yolk is set to your preference. Remove from oven; place the custard dish on a rack and let sit for a minute before serving. Eat directly from the custard cup, or run a knife around the edge and transfer to a plate.

(202 calories/serving, GL=0, Glycals=0)