If one is eating and then leaves the house for a few minutes without making a Brocha Acharona, when he returns and wants to continue eating, does he have to make a new brocha?
If you had in mind at the time you left to continue eating, you may do so when you return without making a new brocho. This applies to bread, mezonos or the fruits on which the brocho achronah is “Al Hapeiros” (grapes, figs, pomegranates, olives and dates).
However, if you ate other foods, you will need to make a new brocho when you return if you want to continue eating, even if you had in mind when you left that you will continue eating when you return.
However, since there are opinions that hold that in all circumstances, one would require a borocho achronah on the food that you had eaten already as well as a new brocho to continue eating, this situation should be avoided altogether.
שו”ע או”ח סי’ קעח ס”א-ס”ב, בן איש חי (שנה א’ פרשת בהעלותך)