Can I just steam spinach and then puree it?

Yup I do that. But a point to note... I use the Philips Avent steamer cum blender... but I would discard the water that is produced from the steaming of spinach as I read that the water is high in nitrates. Personally, I discovered that the steamed spinach can be pureed without any additional water. If I find it too dry/thick before feeding lo (coz I froze the big batch), i would add a dash of water/milk when it thaws.