The cooking time for greens can vary depending on the type of greens you are using and the cooking method. Generally, leafy greens cook relatively quickly compared to tougher vegetables. Here are some common types of greens and their approximate cooking times:
Spinach: Cooking time is very short, usually 1 to 2 minutes. It wilts and cooks down quickly.
Swiss chard: Cook for about 3 to 5 minutes. The stems may take a bit longer to soften.
Kale: Cooking time is around 5 to 8 minutes, depending on the variety and how tender you want the leaves to be.
Collard greens: Require around 15 to 20 minutes of cooking time to become tender.
Mustard greens: Cooking time is about 5 to 10 minutes, depending on the size and age of the leaves.
Bok choy: Cooking time is around 3 to 5 minutes, depending on the size of the bok choy.
Beet greens or turnip greens: Cook for about 5 to 10 minutes until tender.
Keep in mind that some greens, like spinach, will significantly reduce in volume as they cook, so you may need to start with more than you think you'll need. Cooking times may also vary depending on the specific recipe and the cooking method, whether you're sautéing, blanching, steaming, or braising the greens.
The goal is to cook the greens until they become tender but still retain some texture and vibrant color. Overcooking can result in a loss of flavor, color, and nutrients, so it's essential to keep a close eye on them while cooking.