The oven is a product created by the folks over at PieDAO that we use to minimize gas costs. It allows users to pool ETH into the contract which in essence will mint each of the basket tokens at once instead of individually per each transaction.
Once the amount of pooled ETH meets a threshold of 10 ETH, the oven automatically mints the basket tokens. Our systems will check every 15 minutes to see if the threshold is reached. When it meets the threshold and the tokens are minted, you can then withdraw the tokens to your wallet using the "claim" function.
One thing to note is that this process is not entirely gas free. Although it saves up to 97% of the gas costs, a small transaction fee is still required on the user side. The process for using the oven can be seen below.