Different vegetables take different amounts of time to cook in a steamer. If your steamer didn't come with recipes for various vegetables, you can test out the following times. Once you figure out the exact amount of time each one takes, you should set a timer to get consistent results every time. Soft leafy greens: 3 minutes Fresh peas: 3 minutes Broccoli and cauliflower florets, green beans: 5 to 7 minutes Potatoes, carrots, squash, turnips: 8 to 20 minutes Kale and collards: 10 minutes