Q:

Does kidush bimkom s'uda need to be before the s'uda?

Anyone fulfilling his obligation of hearing kidush must eat a meal (or a nominal meal) at the same time and in the same place. There are details &dash see Shulchan Aruch, Orach Chayim 273 — but that's the general rule. My question is whether the meal must follow the kidush or whether, on the contrary, even a meal concluded with kidush is sufficient for the requirement of eating a meal with kidush.
A hypothetical to which my question applies is that of someone who did not hear kidush, ate a meal (or a nominal meal), then realized his error (one may not eat before kidush) and made or heard kidush immediately on concluding his meal (before the meal's after-b'racha, or perhaps after). Would he then need to eat after kidush also?

A:

The Talmud (Pesachim 102a) says that if a group was eating and finished after Shabbat started, they take one cup of wine and recite bentiching on it, and take a second and say Kiddush on it. Ran (20b in the Rif, s.v. Kos Rishon) writes:

ואע"פ שאינו אוכל כלל לאחר קידוש היום כיון שגמרו שם סעודתם מקום סעודה מיקרי:‏
  Even though they are not consuming anything at all after Kiddush, since they finished their meal there, it is still called the place of the meal.

Rama, when quoting this in OC 271:6, notes a dissenting opinion who requires one to consume food after Kiddush in the above circumstance. This opinion, that of Rosh (Pesachim 10:7), does not allow the prior food to count because in this case it was a meal eaten on a weekday, not one eaten for the honor of Shabbat. Thus it is reasonable that even Rosh agrees that it is possible for a meal preceding Kiddush to establish the Kiddush as being in the place of a meal.

