Chef John's Sweet Potato Casserole
Unlike many sweet potato casseroles, this one is not too sweet. It smells so amazing, with subtly sweet potatoes accentuated with maple syrup and a pistachio topping. It's a wonderful combination of taste and textures.
The sweet potatoes I used may be called yams at the store, but the fact is that all "yams" sold in American supermarkets are really varieties of sweet potatoes. My recommendation is for using Garnet yams if you can find them. If you can't, literally any other variety will do.