Odessa-Style Mushrooms

Mom made these many years ago, and they were the first mushrooms I liked (the butter, cream, and sour cream helped). Now, I like many preparations of mushrooms, but these are still the best (the butter, cream, and sour cream STILL help). Although my family has never done the traditional green bean casserole for Thanksgiving, when I volunteered for a vegetable side dish this year, I wanted to do a take on the concept. Not everyone in the family is open to mushrooms, so with the help of my brother, I divided a 9x13 dish into two compartments and put some fox point green beans with shallots in one side and in the other, Odessa-style mushrooms. The idea was that a mushroom-open person could put them together into one dish. I quite liked it. I liked how the green beans cut the richness of the mushrooms, and I liked, well, everything about the mushrooms. The mushroom recipe is from "Russian Regional Recipes" by Susan Ward.

2 1/2 -- 3 1/2 oz butter
4 scallions, finely chopped
1 lb button mushrooms; I quartered them so they could be cohesive with the green beans
1 T flour
salt, pepper
4 oz sour cream
3 oz cream
2 oz grated hard cheese (recipe says cheddar, lancashire, or caerphilly; I used an asiago/parmesan/romano blend)

Preheat oven to, let's say, 350. Melt 2 oz butter in frying pan over medium heat. Add scallions, saute briefly.
Stir in mushrooms and continue to cook 5-6 minutes until they are getting soft and brown.
In a small bowl combine 1/2 oz butter and flour; work to a paste.
Stir the paste into the mushrooms; cook for 3 minutes.
Add the sour cream and the cream.  Season generously to taste.
Place the mushrooms in a casserole and sprinkle the cheese "and the remaining butter" on top (I did not add more butter, and do not think it is needed. There is plenty of fat).
Bake for 20-25 minutes.