How to use kitchen equipment you already own to make a double boiler, rather than buying an extra kitchen tool.
Step 1: What Does It Do?
A double boiler is used to melt something like chocolate that is too delicate to be melted directly over a flame. They can be quite expensive but are easy to make using items that you probably already have in your kitchen.
Image courtesy of KVDP: http://commons.wikimedia.org/wiki/User:KVDP
Step 2: Components
To do this, you'll just need a saucepan and a metal bowl. Glass can work as well (with the added bonus of being able to see the boiling water through the bottom), but if you go this route you must be careful. Some glass bowls might not be safe to heat this way.
Step 3: Assemble!
Be sure the bowl fits snugly into the saucepan and only goes about halfway into the pan. You do not want the boiling water to ever touch the bottom. It is also important that you do not run the risk of the bowl sliding into the pan and mixing water with the ingredients you are trying to melt.
Most of the time when you are melting something, you will not use the lid. WIth the lid on, it is difficult to keep condensation from getting into the ingredients.
Be careful when you are using this - the bowl can get extremely hot!
Step 4: Remixing
Now that you know how easy it is to hack your own kitchen tools, you're basically unstoppable! Try using a metal colander instead for a handy vegetable steamer.
Step 5: Applications
Or, just start melting to your hearts content. Make some brownies (with real chocolate!), or fudge, or my favorite pie: chocolate meringue.
Photo courtesy of Steven Labinski: http://www.flickr.com/photos/texascooking/5805147477/