Instructions

1. Preheat oven to 350°. Coat a 9x13 inch baking dish with butter or olive oil.
2. Prepare the vegetables. Rinse green beans, remove stems and cut in to 2-inch pieces. I usually purchase pre-sliced mushrooms. If you have whole mushrooms, rinse and then slice.
3. Caramelize the onions. Peel the onions and slice in half from root to top. Lay the onions flat side on the cutting board and slice again lengthwise from root to top. Next slice the onions crosswise into thin strips. Heat a large skillet over medium high heat and add the onions with a pinch of salt. Allow to cook for about 20 minutes, stirring occasionally to prevent sticking, until the onions become translucent and the moisture has cooked down. If the onions begin to brown to quickly or stick to the bottom of the pan add a little more oil. Once the onions have cooked down, it’s now time to start browning them which caramelizes the naturally occurring sugars in the onions. Allow the onions to cook 10 to 15 minutes longer until nicely browned but not burned. Only stir if they are starting to burn as too much stirring will prevent the caramelization process. Once the onions are thoroughly browned, transfer to a separate dish to cool. Note: Caramelized onions can be kept for up to 2 weeks in a sealed container and refrigerated. They are great to have on hand to top off steaks and burgers.
4. Make the mushroom sauce. To the same skillet that you cooked the onions in, add 2 tablespoons butter and a drizzle of olive oil. Once the butter has melted add the mushrooms. Sauté mushrooms over medium heat until they release their moisture. Continue cooking until the moisture cooks down completely and the pan begins to brown. Add ½ cup chicken broth and deglaze the pan by scraping all of the browned bits from the bottom of the pan with a flat headed wooden spoon or spatula as the broth simmers. Continue to simmer the broth until reduced by half. Add the heavy cream and cook for a few minutes more until the mushroom sauce becomes thick and bubbly then remove pan from the heat.
5. Cook the green beans. Fill a large pot of water to boil the green beans in. You can get this started while caramelizing the onions to save time. Bring the water to a boil and then add 1 teaspoon of salt and the green beans to the boiling pot. Boil for about 10 minutes or until green beans are tender when pierced with a fork. Drain the green beans well and then add to the mushroom mixture. Toss to thoroughly coat all of the beans.
6. Transfer the green beans to the prepared baking dish and top with caramelized onions. Bake at 350° for 20 minutes if the beans are still warm or 30 minutes if beans have been prepared in advance and need to be reheated.