1. Preheat oven to 375.
2. Mix together the chopped cheese, bacon, and chives and season with the salt & pepper. In a separate bowl, beat the eggs. Brush the muffin tins with the butter or spray well.
3. Using a teaspoon, fill the mini-muffin cups halfway with the cheese mixture. Using a ladle, fill the cups to just below the edge with the beaten eggs.
4. Bake until golden, about 12 minutes. Remove and let cool to handle.