I served this yesterday to family and a friend to good reviews:
Mashed Sweet Potatoes with Banana My simpler riff on Andrew Perry Lang’s recipe from Serious Barbecue.

5 or 6 sweet potatoes, washed
1 tsp salt +, to taste
1 banana
2-3 ounces butter
½-3/4 cup milk or soy milk
¼ tsp ground cinnamon
Finely ground black pepper, to taste

Prick potatoes and banana. Bake in oven until very tender. Or wrap potatoes in foil and grill or smoke until tender (it may take a couple hours in the WSM). No need to foil the banana -- cook until tender and black. The banana will cook much quicker than the sweet potatoes.

Wearing rubber gloves (potatoes are hot!) split potatoes and banana and scrape flesh into a sauce pan. Mash with potato masher until smooth. Add all other ingredients and ½ the salt, and simmer on stovetop until hot. Results should be light and fluffy. Salt and pepper as necessary to taste.
APL's original version looks great. It involves more, butter, cream, etc. and the further step of baking everthing in a baking dish.

Looking for something new for a pitch-in next month, I just made a trial run of these.

I think we have a winner, they are very good.

Thanks for the recipe.