Green Beans with Mushrooms Onions and Mornay Sauce

These Green Beans with Mushrooms, Onions and Mornay Sauce is a classic, homemade side dish that’s just perfect for the holidays ahead. It’s a quick and easy, fresh from scratch side that everyone is guaranteed to enjoy!

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.

Why You’ll Love this Recipe

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.

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.

Step-By-Step Instructions

The first step is to make your cheddar mornay sauce and set aside until ready to use.

The second step is to 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. 

The third step is to cook your onions followed by your mushrooms.

The final step is to sauté the green beans, then ladle the mornay sauce onto a large platter, top with green beans followed by the mushroom and onion mixture. 

Hope you guys add this tasty side dish to your holiday menu this year. I know you’ll love it!

Please let me know if you give the recipe a try. And if you have any questions about the recipe, just drop a comment below. Enjoy!

Green Beans with Mushrooms Onions and Mornay Sauce

Author: MaryAnn Dwyer

Servings: 8 servings

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These Green Beans with Mushrooms, Onions and Mornay Sauce is a classic, homemade side dish that's just perfect for the holidays ahead. It's a quick and easy, fresh from scratch side that everyone is guaranteed to enjoy!

Prep Time 10 minutes mins

Cook Time 30 minutes mins

Total Time 40 minutes mins

Ingredients  

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

Beans

• 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

Instructions 

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.

Beans

• 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.

Notes

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.

Keyword: green beans, holidays, mornay sauce, mushrooms, onions, Thanksgiving

Cuisine: American

Course: Side Dish