I'm thinking of making mock eel for a Christmas side (it's potluck and just about everything you can think of is covered), but I'm not sure how to manage this as a make ahead dish.

I'm thinking I'll fry the mushrooms at home, and bring the sauce and saute in a pan at the last minute once I'm there. Does this sound doable? Have you ever done it? Any tips would be welcome. I did a dry run just making the mock eel with some button mushrooms I had on hand, and was very pleased. Anybody else make them with anything other than shiitake?