Mushrooms -- I toss the whole cremini mushrooms after cleaned and the end of the stem removed with olive oil, rosemary, salt and pepper. Then bake on a cookie sheet lined with aluminum foil for 20 -30 minutes at 400F until soft and lightly golden brown. You don't want them over cooked and falling apart.
Transfer the mushrooms to a casserole dish sprayed with Pam or lightly greased.
Sauce -- In a medium size sauce pan add the oil and heat to medium. Add the onion and garlic and cook until the onion begin to brown, keep on medium low heat, you don't want them to burn or get crispy, just lightly saute.
Sauce II -- after the onions are done, add in the flour to slightly thicken. Then add the wine and bourbon and let reduce and scrape up any drippings then add the chicken broth and bring to a medium heat to make a sauce. Let it cook 2 minutes to heat up and slightly reduce then add the heavy cream and season to taste. Cook 3-4 minutes to slightly reduce and thicken.
Pour over the mushrooms in the casserole dish.
Topping -- In a measuring or mixing cup melt the butter in the microwave, just 10 seconds and add the bread crumbs and mix well. Top the mushrooms.
Bake 20 minutes on 400F until bubbly and the crust is golden brown.
This is a lighter sauce which is great when served over sliced pork or chicken. The sauce is absolutely wonderful over butter noodles, rice, couscous, and just about anything.