by packetbob @ instructables.com:
I decided to put together a toaster oven and wanted something that could handle large boards and possibly do small production runs. Doing a web search, you will find many options for toaster oven reflow controllers. They range from one-off designs to DIY boards to full kits. A large number of them are Arduino based. Some controllers just allow the oven to plug in (so you don’t need to take the oven apart) while others integrate completely inside the oven (more work but a much better product in the end).
Making A SMD Reflow Oven – [Link]