Fall is the season of the sweet potato in Japan. The beloved starchy tuber, called satsumaimo, is featured in many favorite Japanese dishes from tempura to ice cream. This delicious casserole pairs well with chicken or roast pork.

4 sweet potatoes, boiled, peeled and diced
4 tbsps butter
1/4 pound unsalted pistachio nuts
2 tbsps brown sugar
Pinch of nutmeg
1/4 cup sake
1/4 cup panko bread crumbs

1. Preheat oven to 350F. Peel and dice sweet potatoes.

2. Butter a gratin dish with 1 tablespoon of butter. Add the diced sweet potatoes. In a food processor, finely grind the pistachios; add the brown sugar and nutmeg and whirl to blend. Sprinkle pistachio mixture on top of sweet potatoes. Pour in sake.

3. Cut the remaining butter in small pieces and dot over sweet potatoes. Top casserole with panko bread crumbs and bake for 25-30 minutes, or until golden brown. Serve immediately.