Last night was my first attempt to use the slow cooker as a steamer. Huffington Post wrote about this technique and Grant Achatz opened up about his love for the crockpot in Food & Wine Magazine. (Achatz even uses one in a prix-fixe as a departure from all the fancy and precise dishes -- the actual container is served at the table for a family style dish). Even The New York Times is in the conversation. It's happening: The Slow Cooker Revolution phase 2.
The most creative and sophisticated way to steam via crockpot is to create a flavorful bed for the food. Lemongrass or herbs can work for fish or vegetables and will impart added nuance to the dish. I didn't have either and after trying to rig up something with bamboo sticks, I decided to just use my steamer—that flimsy red thing below—that fit perfectly in the cooker. I went super simple-an inch of water and raw asparagus lying on the red steamer. (There is a "steamer" button on the slow cooker but I don't know what it does exactly...must look that up!) So I just set it to high for 30 minutes: 15 to heat up and 15 to steam. It worked pretty perfectly. Asparagus was cooked but still firm. I transferred it to a plate and topped with some diluted cheese sauce I had made for the kids Mac and Cheese and parmesan cheese. Huge hit with Michael and, of course, Mack!
One more thought: could the slow cooker also sous vide? Does it hold the liquid at a reliably steady and low enough temperature...The Huffington Post explored that too (why is the HP so schooled in the slow cooker??!) and suggested that it CAN be done if you are a supersonic engineer that could rig a DIY temperature controlled device to the slow cooker wires. Um, no.