1Preheat oven to 350. Prepare ranch style white sauce.
Melt butter in a small saucepan over low heat. Stir in flour, cook 1 to 2 minutes, stirring constantly. Using whisk, stir in milk; bring to boil. Cook, whisking constantly, 1 to 2 minutes or until thickened. Stir in dressing mix and pepper. Set aside
This makes 1 1/2 cups...I sometimes double this for more sauce.
2Place 1 tbsp olive oil in medium skillet, heat over med high heat; add onion and garlic, cook 2 to 3 minutes or until tender. Remove half of onion mixture. Set side.
3Add mushrooms to the skillet and cook about 5 minutes or until tender. Combine mushroom mixture, beans and sauce in 1 1/2 quart casserole.
4Add 1 tablespoon of butter to a medium skillet, heat over med high heat. Add bread crumbs to skillet; cook 3 to 4 minutes or until crumbs are golden. Stir in reserved onion mixture, parmesan and parsley.
Sprinkle bread crumb mixture over casserole. Bake, uncovered 35 to 40 minutes or until heated through.
I usually double or triple this recipe for big get - together's