What is the best way to cook the sweet potatoes before assembling?

Thanks for your interest in this recipe and all the answers by Food 52er's. I boil them myself because I am usually too impatient to roast them. But roasting is certainly more hassle free. But I will next time try Anthonia's microwave technique. Thanks ladies!

I microwave them, with great success, especially for a dish like this. Cut unpeeled sweets crosswise into 2" chunks, put a tablespoon or 2 of water in the bowl, cover loosely, cook on 80% power for about 5 minutes. Check for doneness, flip over in the bowl, microwave a few more minutes or as long as necessary until they're tender. Let cool, covered. Skins will easily peel off. Easy! ;o)

I think roasting is easiest! Wrap each potato in foil, then roast in a 300 to 350° F oven until tender (check at 40 minutes, but it could take over an hour). Like described here: https://food52.com/blog/18490-sweet-potato-casserole-however-you-like-it-marshmallow-topped-or-not

You could also boil them! In a pot of water until tender.

Hey Katherine! This recipe has not been cooked or edited by the Food52 staff or test kitchen, so I can't speak for it directly, but it does sound delicious. For sweet potato casseroles in general, boiling and baking both work well. Here are some guidelines from a recent article on ways to do each. To boil: peel and cut into chunks; start checking after 30 minutes to see if they’re tender. To bake: whole, peel on, pricked with a fork, oiled, wrapped in foil; 400° F for 45 minutes to an hour.