Akane vs. Ranma! I'll Be the One to Inherit Mother's Recipes!

Akane vs Ranma: Okā-san no Aji wa Watashi ga Mamoru! (あかねＶＳらんま　お母さんの味は私が守る！) is the third Ranma ½ OVA.

When Kasumi falls ill and leaves the Tendo home without a chef, Nodoka Saotome, Ranma's mother, pays a visit and offers her assistance. The family isn't too happy though when she offers to help teach Akane how to cook. Akane's desire to learn to cook is even more intense, because she recently discovered her mother's old cookbook. Ranma (disguised as the Tendo's cousin Ranko) decides he should help in the kitchen in order to insure Akane doesn't accidentally kill his mother with her notoriously bad cooking.

Trivia

 * In the manga counterpart, there is no mention of Mrs. Tendo or her old cookbook. Akane's desire to assist Mrs. Saotome comes simply from wanting to be better than Ranma.