These are also called "cassava" you may have heard of these?
It is important to note that there is a spine in the centre of them, make sure you pull it out. You also want to peel them, you may need a very sharp knife to do that as a peeler just won't do!
As for a recipe, make a tropical themed vegetable stew!
Start with a good veggie stock and add any of these: Onions, garlic, peppers, carrots, cauliflower, greens of your choice, plantain (If you can find it), summer squash, tomatoes, chickpeas, corn, and the cassava!
(If you don't have cassava, a mixture of celery root and potato is also good!)
You can spice it with: Hot peppers of your choice, oregano, and fresh cilantro (Parsley if you don't like cilantro).
This is a very special recipe to me, although it probably doesn't look like one. I make it all the time and it's wonderful! More recently with yellow yam. Mmmmmm!