Almost any vegetable may be used here. I use 1/2 head cauliflower, 1 stem of broccoli, 1/2 butternut squash, 1 cup green beans, and 1 bell pepper) Potatoes also work well as do root vegetables, carrots, eggplant, zucchini and probably just about whatever you have on hand. Frozen or pre-chopped will cut back on the prep time.