In my C.S.A. ("community supported agriculture") box from next week, there were - among other veggies - 2 sweet potatoes and 2 yams. I wasn't quite sure what to do with them. So when I read the recipe of this yam and sweet potato pie in The Big Sur Bakery Cookbook (p. 146), I immediately wanted to try. It is very simple : 1 layer of sweet potatoes soaked in a mixture of egg yolks/heavy cream + some shredded cheddar + 1 layer of yams soaked in the same mixture; in an oven safe dish, covered with aluminum foil; bake at 350 F for about 1 hour; remove the aluminum foil and continue to bake for about 15'. Let stand at least 15' before eating.