Sweet potato: If you are making your own sweet potato puree check out how to do it here! You will want to plan ahead if you are since baking the sweet potato takes time.
You can use a food processor to chop the nuts into small pieces. I like to then put all the other ingredients in the food processor and let it do the mixing. Also, make sure the pie dish is well greased because it can be hard to get out otherwise. I like to buy my tapioca flour/starch in bulk from a local health foods store since it’s usually cheaper, but it can be found online or prepackaged located with alternative flours at most grocery stores.