01 - Place eggs in a saucepan, cover with cold water by one inch, and bring to a boil. Reduce heat to low and simmer for 9 minutes. Transfer eggs immediately to an ice water bath and cool completely, then peel and coarsely chop.
02 - While the eggs cook, arrange bacon slices in a skillet over medium heat and cook until golden and crisp. Transfer to a paper towel-lined plate to drain excess fat, then crumble after cooling.
03 - In a mixing bowl, gently combine chopped eggs, mayonnaise, Dijon mustard, halved cherry tomatoes, crumbled bacon, and chives if using. Season thoroughly with salt and black pepper.
04 - Spoon an even portion of the egg salad mixture into the center of each lettuce leaf.
05 - Fold or roll the lettuce leaves to enclose the filling and serve immediately for optimal freshness.