1. There is a dispute about when one is liable for kneading on Shabbos.
2. One is not allowed to put a lot of wheat into a windmill if the mill will continue grinding the wheat throughout Shabbos.
3. There is a dispute about the reason for this law (#3).
4. A person is not allowed to put a pot of [uncooked] legumes on a fire immediately before Shabbos.
5. However, a person is allowed to put a pot of food containing raw meat on a fire immediately before Shabbos.
A BIT MORE
1. The Gemara discusses a case in which one person poured flour into a bowl, and another person then poured water into the bowl. Rebbi: The second person is liable for the Melachah of kneading on Shabbos. Rebbi Yosi b'Rebbi Yehudah: The second person is only liable if he proceeds to mix the flour and water together.
2. While most Melachos can be started before Shabbos even if they continue on their own during Shabbos, this is an exception to the rule.
3. Rabah: It is because the mill makes a lot of noise, and it is forbidden to start a machine before Shabbos when it will make a lot of noise on Shabbos. Rav Yosef: It is because one is supposed to ensure that his vessels rest on Shabbos.
4. This is because of the concern that he will stoke the coals in order to make the dish cook quicker.
5. There is no concern that he will stoke the coals in this case, since meat takes a long time to cook in any event, and he intends to eat the meat only on Shabbos day. He therefore will not stoke the coals.