I burnt water

I got this bamboo steamer as a housewarming gift, so I decided to steam some pot sticker dumplings and pork buns that I got from T&T. I boiled up some water and steamed them for about 11 minutes, and they tasted really good. So I put on another batch and steamed them too. Unfortunately, the water completely boiled away and the food residue that had dripped from the bamboo steamer burnt inside the pot. Now it's all black on the bottom. What a mess.