Hard-boil your eggs if needed and let them cool completely. Peel and chop.
Cook bacon until crisp, then drain and crumble.
In a mixing bowl, combine eggs, mayo, mustard, lemon juice, salt, and pepper.
Fold in chopped tomatoes, bacon, and green onions (if using).
Gently spoon egg salad into each lettuce leaf and fold or roll to serve.
Notes
Best served fresh. Store egg salad separately from lettuce and assemble just before eating. Try adding avocado or seasoning with paprika for extra flavor!