Hilchot Berachot 4:7-8 (Deciding to stop eating… then changing your mind)
5:39 pm
If you decide to stop eating, but then change your mind, can you continue without making a new beracha? (The Rambam and the Raavad disagree on this point.) What about if you say that you are going to say Birkat HaMazon, or Kiddush (if you’re eating on late Friday afternoon)or Havadalah (if you’re having seudah shlishit) – in these cases, must you stop and do so, or is it acceptable to change your mind and continue?