Regarding one who pauses in their Shabbat lunch, recites the blessing usually said after a meal, and then continues to eat their third meal straight away.¹ Some say that doing so does not fulfill the commandment to have three meals on Shabbat, for even though they recited the blessing after the meal, it is still considered one long meal - three meals refers to evening, morning and afternoon.² I asked whether this practice was valid or not.

footnotes: ¹ Such a practice is quoted in Halakhot Gedolot 7:31, and attributed to the Rosh in Tur Orach Chaim 291. ² This is the opinion cited in Tosafot on Shabbat 118a:1

They responded: "Let me enlighten you and show you the way," (Psalms 32:8) for this matter can be learned from the Torah of our teacher Moses. For it is written (Exodus 16:25) "Eat it today, for today is a sabbath of God; you will not find it today on the plain." Just as the days are separated from each other¹, so too do the times of the three meals need to be separated from each other.

footnotes: ¹ i.e, the three mentions of the word 'today' in the verse