staple in Asian stir fries and soups, pac chois have a mild mustard flavor with background sweetness. Also known as Pak Choi and Bok Choi. Green stem varieties tend to have more flexible stems than white stem varieties. To prevent breakage post harvest, allow to wilt slightly after cutting, then pack into boxes. Hydrocool to restore. Though pac choi prefers cool weather, most varieties (see variety descriptions) perform relatively well in warm weather.