Can I use a simple bain marie to steam broccoli? I dont have a microwave or a steamer basket. Alternatively, could I just put them in a colander over the pot?
Put it in a pot with just enough water to cover the bottom (you can use less but if it's your first time, I would recommend this amount). Put the lid on, the heat on high, and the water will steam the broccoli.
Broccoli works well for this because the shape means that very little surface area of the broccoli will actually touch the water. When you get used to this cooking method, you can figure out how much water to use so that it all evaporates by the end of the cooking process too.