In a small saucepan, heat an inch of water over medium-high heat, until boiling.
Add egg, reduce heat to medium, and cover. Let egg cook for 3 to 5 minutes (depending on desired doneness, from runny to barely set).
While egg is cooking, toast bread and slice into thing strips (aka soldiers). Coat generously with butter, placing a dollop of Bonne Maman Preserves on a few, reserving a few for dipping.
When cooked, run egg immediately under cold water until cool enough to handle.
With a butter knife, crack the top edge of the egg and gently slice off the top portion. Place egg in Le Creuset egg cup and serve with toast soldiers.