Bring plenty of salted water to a boil.
Add the lettuce, blanch for 2 minutes and drain.
Peel the eggs and stuff each lettuce head with an egg.
Wrap the thinly sliced ham or bacon around the lettuce heads and tie.
Melt butter in an ovenproof dish and coat the lettuce with the melted butter.
Arrange the lettuce heads in the dish, pour over bouillon and heat 5 to 10 minutes in a preheated 350° oven.