The final meal before Tisha B’av is called the “seuda hamafsekes”. Various customs are attached to this meal which are meant to symbolize our mourning. We can only eat one cooked dish (raw foods can also be eaten). Rama 552:5 says that our custom is to eat a hard boiled egg. We also drink water and eat bread. At the end of the meal we dip the bread into ashes and announce that this is the meal of Tisha B’av.
The meal must be an actual meal rather than just a symbolic gesture. The Tur brings from the Ramban strong words against those that eat an entire meal, and then after having no appetite, they eat the seuda hamafsekes. The Rama says in the name of the Maharil that those who will otherwise be unable to fast can be lenient, although the Mishna Berura is not happy with this opinion.
Two options are given that will satisfy all opinions. First, the Magen Avraham 552:12 suggests to eat a meal before mincha which should consist of only one cooked item. You can eat this meal with other raw foods (i.e. salad). This will be considered a seuda hamafsekes in its own right. After mincha you can then eat the symbolic egg and bread. Another option is from the Chayei Adam brought in Shaar Hatzion 552:18 to eat your large meal with different courses earlier in the day. Then, closer to nightfall you will have some appetite for the seuda hamafsekes. The Mishna Berura adds that if someone will have a hard time fasting, they can be lenient and follow the Rama, just should be careful to leave over some appetite for the seuda hamafsekes.

Rabbi Tzvi Aryeh HymanMir Yeshiva, Jerusalem- [email protected]