Question: May one eat matza balls (kneidlach) or crackers before Pesach?
Answer: While the halacha is that one mustn’t eat matza on erev Pesach (Rambam, Chametz Umatza 6:12; Rema OC 471:2), the Mishna Berura (471:12) writes that some have the minhag not to eat matza from Rosh Chodesh Nissan.
R’ Moshe Feinstein (Igros Moshe OC 1:155) notes that some abstain from eating matza for 30 days before Pesach as according to one view in the Gemara (Pesachim 6a) this is when our Pesach preparations begin.
The Baer Heitev (OC 471:5) writes that one may eat crackers providing that there is no possibility that they could be fit for matza. Likewise, the Shulchan Aruch (OC 471:2) writes that one can eat egg matza on erev Pesach before ‘the end of the fourth hour’ (when one has to stop eating chametz). Thus, R’ Moshe Feinstein writes that when erev Pesach falls on Shabbos, one can use egg matza for lechem mishna on Friday night and in the morning.
R’ Shmuel Wosner (Shevet HaLevi 8:117) writes that this prohibition includes cakes baked from matza meal (See Piskei Teshuvos 471:3). Many sefardim follow R’ Ovadia Yosef (Yabia Omer OC 6:39) who writes that only matza itself must be avoided.Once food is boiled, it takes on a different form. Thus, the Mishna Berura (444:8; Shaar Hatziyun 444:1) writes that one may eat matza balls on erev Pesach.