Since no one has answered your question I’ll give it a shot. I’ve never tried butternut walnuts but with black walnuts I wait until they fall to the ground and then gather them. As to enjoying them, you might try making a pie. My dad used to make the most amazingly delicious black walnut pie. He used the basic pecan pie recipe in the old Joy of Cooking and just substituted the walnuts for the pecans. You’d be amazed at how good it tasted, specially with a little ice cream on top. Anyway, butternut walnuts might make a pretty good pie too.