You can steam broccoli in an Instant Pot pressure cooker with or without a steamer basket. I have used a steel steamer basket that comes along with the Instant Pot packing. But if you don't have a steamer basket, just put broccoli florets in the inner pot and 1/2 cup of water and follow the steps. But I highly recommend using a steamer basket to get perfectly crunchy and tender broccoli.