Put the butter in a 3 1/2 or 4 ounce ramekin. Microwave to soften so it spreads easily, and rub it around the inside of the ramekin. Add cream. Gently crack the egg into the ramekin. Sprinkle with the cheese and some chives. Bake in a preheated 425° oven for about 11 minutes until white is firm but yolk is still soft.