- In a small skillet, cook the bacon until crisp and golden brown. Drain and let cool. Finely chop. Keep the fat for the mayonnaise.
- In a large bowl, combine the egg yolk, mustard, lemon juice, and pepper. Season with salt. Add the first third of the oil, drop-by-drop, whisking constantly. When the mayonnaise begins to set, add the remaining oil and the bacon fat in a thin stream, beating constantly. Add the bacon and adjust the seasoning. Keep refrigerated.