SERVES 4 -6 (change servings and units)
1 ounce imported dried wild mushrooms, preferably porcini, well rinsed
8 tablespoons unsalted butter
1 cup whole dried kasha (buckwheat)
salt, to taste
2 large onions, chopped
10 ounces fresh white mushrooms, wiped clean and sliced
1 cup sour cream
1/2 cup chicken broth
1 Soak the dried mushrooms in 2 cups tepid water for 2 hours. Remove the mushrooms from the soaking liquid, pat dry with a paper towel, chop and set aside. Strain the liquid through a coffee filter, transfer to a saucepan, and bring to a boil. Reduce the heat and keep at a bare simmer while preparing the next step.
2 Melt two tablespoons of the butter in an ovenproof medium sized casserole over medium heat. Add the kasha and stir for 3 to 4 minutes. Add the simmering liquid and salt, then reduce the heat, cover, and simmer until the liquid is absorbed, 15 to 20 minutes.
3 Meanwhile, melt another 4 tablespoons butter in a large skillet. Add the onions and saute over medium heat for 5 minutes. Add the fresh and the wild mushrooms and saute, stirring, until nicely colored, 15 to 20 minutes.
4 Preheat the oven to 375 degrees F.
5 Stir in the mushrooms and onion mixture into the kasha. Blend together the sour cream and stock and add to the kasha. Stir well, then dot the top of the casserole with the remaining 2 tablespoons butter and bake until the top is lightly browned, 15 to 20 minutes.
6 Serve at once.