These Green Beans with Mushrooms, Onions and Mornay Sauce is a classic, homemade side dish that’s just perfect for the holidays ahead. Nothing canned here. It’s a quick and easy, fresh from scratch side that everyone is guaranteed to enjoy!
Ok folks. Two weeks until Thanksgiving.
NO NEED TO PANIC. Sorry for yelling, but really, there’s NO NEED TO PANIC. You’ve got this.
You’ve got more than enough time to plan things and come out lookin’ like the Ina Garten of Turkey Day. And there’s no time like the present to get the ball rolling and organize your menu.
This year we’ll be enjoying the holiday with family. My sister Carolyn and brother-in-law John will be hosting, so I won’t be doing the turkey. I’m in charge of mashed potatoes, another side dish which is sure to be these Green Beans with Mushrooms Onions and Mornay Sauce, some homemade dinner rolls and of course Mr. Picky’s fave…canned cranberry sauce.
Yes, I know, what food blogger doesn’t go the extra mile and make homemade cranberry sauce on the biggest food holiday of the year? Me. Been there, done that, and if the cranberry sauce I’m servin’ doesn’t have the lines from the can on it, nobody in my family’s eating it. What can I say? At least they’re low-maintenance.
For the Thanksgiving holiday, Tom grew up eating the famous Campbell’s Soup green bean casserole with the French’s French Fried Onions. Actually, so did I, but I was never really a fan. So I knew if I’d want to change things up and make a newer, more homemade version, it would have to be good to get Mr. Picky’s approval.
I love the magazine, The Local Palate, and when I saw the recipe for Not Your Mamma’s Green Bean Casserole in last year’s Winter 2020-2021 issue, I knew it would win Tom over. I made it last Thanksgiving and numerous times since for family and friends and it’s won everyone over.
Green Beans with Mushrooms Onions and Mornay Sauce Ingredients
- fresh green beans
- yellow onion
- salt and pepper
- olive oil
- shiitake mushrooms
Mornay Sauce Ingredients
- garlic cloves
- bay leaf
- fresh thyme sprigs
- all-purpose flour
- white wine
- salt and pepper
- shredded white cheddar cheese
It’s got fresh green beans, not canned, caramelized onions and shiitake mushrooms all atop a creamy white cheddar mornay sauce that makes for a holiday side dish that family and friends will request all year long, not just for the holidays. Enjoy!
A Few Cook’s Notes for Green Beans with Mushrooms Onions and Mornay Sauce
The recipe mentions that you can use oyster, shiitake or cremini mushrooms. I chose shiitake for today’s recipe, but I’ve also made this dish with baby bella mushrooms.
You’ll add your green beans to a pot of boiling water and cook them for about two minutes which will leave the beans nice and crunchy. If you like your beans a bit softer, cook for an additional minute or two.
More Delicious Holiday Side Dishes to Enjoy
Green Beans with Mushrooms Onions and Mornay SaucePrint Recipe Pin Recipe
- 2 lbs. green beans, stemmed
- 3 Tbsp. butter, divided
- 1 large yellow onion, sliced and roughly chopped
- salt and pepper, to taste
- 1 Tbsp. olive oil
- 1/2 lb. shiitake mushrooms, sliced
- 1 1/2 cups cheddar mornay sauce
Cheddar Mornay Sauce
- 2 Tbsp. butter
- 1 shallot, finely chopped
- 2 small garlic cloves, minced
- 1 bay leaf
- 2 thyme sprigs
- 3 Tbsp. all-purpose flour
- 1 3/4 cups milk
- 1/4 cup white wine
- salt and pepper, to taste
- pinch of nutmeg
- 1/2 cup shredded white cheddar cheese
- Fill a large pot with water. Add one teaspoon salt. Bring to a boil. Fill a large bowl with ice water. Add the green beans to the boiling water. Cook for 2 minutes (1-2 minutes longer if you like your beans less crunchy). Transfer beans to the ice bath. Drain beans and cut larger beans into thirds, smaller beans in half. Set aside.
- Add one tablespoon butter to a large skillet over high heat. Add the onions and season with salt and pepper. Cook for 2 minutes, until just lightly browned. Reduce the heat to medium-low and continue to cook the onions for 15 minutes, stirring often. Remove the onions from the skillet and set aside.
- Return the skillet to medium-high heat and add another tablespoon butter and the olive oil. Add the mushrooms and saute for 2 minutes. Season with salt and pepper. Once the mushrooms are cooked though and lightly browned stir in the caramelized onions and then remove from the skillet and set aside.
- Add the remaining tablespoon of butter to the skillet and cook over medium-high heat. Saute the green beans. Season with salt and pepper. Ladle the mornay sauce onto a large platter, top with green beans followed by the mushroom and onion mixture. Serve immediately.
White Cheddar Mornay Sauce
- In a small sauce pan, melt butter over medium heat. Add the shallots, garlic, bay leaf and thyme sprigs. Cook for two minutes, then discard bay leaf and thyme sprigs. Add flour and cook, whisking constantly for 3 minutes. Slowly whisk in the milk increasing the heat to medium-high. Cook until mixture starts to thicken, stirring frequently. Stir in the wine, reduce the heat to low and continue to cook for 3-4 minutes. Season with salt, pepper and nutmeg. Remove from the heat and stir in the cheese until smooth. Keep warm on your stovetop until you're ready to top with the beans and mushroom and onion mixture.