Note: I prefer to remove the florets from the cauliflower and then steam them. You can also boil them, but steaming them isn't as violent so they tend to stay together. Also, if you are using purple or orange cauliflower boiling tends to remove some of the color.
Fire up your Big Easy.
Lay a single layer of foil inside the basket and/or bunk bed baskets.
Add the cauliflower in a single layer. Try to not over-crowd too much. A little is ok, but stacking them won't result in even roasting.
Lower the basket into the cooker and cook for 10-20 minutes depending on how done you want your cauliflower.
Remove and let cool slightly before seasoning with your favorite seasoning and serving.
Notes
Too cook a medium head of cauliflower all at once I used two bunk bed baskets, both lined with foil. You could get by with a single bunk bed basket and then also line the bottom of the Big Easy basket with foil.