It’s not Thanksgiving without the green bean casserole! This recipe for Green Bean Casserole from Scratch is easier than you think, totally delicious, with just the right amount of holiday nostalgia.
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I LOVE green bean casserole. I love it any way that it’s prepared, even with canned green beans and cream of mushroom soup. I’m not sure about you, but we had the canned green bean version at every holiday, when I was growing up, so there is a special place in my heart for it.
But, if you have never had a scratch made batch, you are in for a treat! It’s so rich, creamy, cheesy and delicious! It’s the ultimate holiday comfort food and it brings back so many memories. So, if I have the extra time, I love to prepare a homemade dish.
Read on for the step by step recipe:
Those fried onions! Insert drooling emoji here.
What you’ll need
- A 9×13 baking dish
- A pot for oil to fry the onions, such as a dutch oven. Or you can use an air fryer. Directions for both methods are below.
- Fresh green beans-cleaned and trimmed
- Fresh mushrooms– cremini, button, or baby bella’s all work so use your favorite.
- Onions– yellow, red, or white, medium sized
- Seasonings– garlic cloves, salt, pepper, yellow mustard powder
- Milk– I have not tried this with plant based milks, so I’m not sure how it will turn out. I use 2% because that’s typically what I have on hand. Half and half, heavy cream, whole milk or 1% will work as well.
- Grated parmesan cheese
- Shredded gruyere cheese, or substitute muenster or mozzarella. Shred it yourself, it melts so much better!
- All purpose flour– to coat the onions before frying
- Canola or vegetable oil– or something you can use to fry the onions that has a higher smoke point.
How to make Green Bean Casserole from Scratch
Clean and cut the green beans.
Bring a large pot of water to a boil. Have a bowl of ice water near by to “shock” the green beans to stop the cooking process and keep the beans bright green.
Blanche the green beans for 4 minutes and remove to the ice bath. Let them hang out in their cold water plunge for 2-3 minutes. Drain and set aside.
Prepare the fried onions- Two ways
You can fry the sliced onions in oil or air fry them.
To fry in oil:
Add the oil to a heavy bottom pot or dutch oven and heat to medium high.
Toss the sliced onions with flour.
Once the oil is hot, add the onions. Cook until golden brown in color. This shouldn’t take too long so don’t walk away, they burn easily! Stir the onions every so often to keep them moving in the oil.
When the onions are browned, remove them to paper towels to drain. Sprinkle salt to taste on the fried onions while still hot. Set aside until ready to top your green bean casserole.
How to air fry:
2-3 onions- red, yellow, or white
1 tbsp olive oil
1/2 tsp Salt
Slice onions in half moons, very thin. Pull slices apart and toss with the oil. Place in an air fryer in a single layer (as best as you can) and sprinkle with salt. Air fry at 350°F for 5 minutes. Shake the onions and fry another 5 minutes.
Shake again, fry at 300°F for 10 minutes, or until crisp.
Prepare the filling
Heat the butter in a large pan over medium heat. Add the mushrooms and cook until softened and the liquid has evaporated, about 5-6 minutes. Add the garlic and cook 30 seconds – 1 minute, stirring often.
Sprinkle 2 tablespoons of the flour evenly over the mushroom mixture, add the mustard powder, salt and pepper. Stir, cook for 1 minute.
Slowly add the milk while whisking constantly over medium high heat. Continue whisking until the mixture comes to a boil and thickens, about 5 minutes.
Remove the pan from the heat and stir in the cheese until melted. Stir in the green beans until evenly coated.
Preheat oven to 350°F.
Lightly spray a 9×13 baking dish and add the green bean mixture.
Top with the fried onions, cover with foil and bake for 30 minutes until bubbly.
Tips and Tricks
Make this ahead: place the mixture in a bowl and store in the fridge until you’re ready to cook, keep the fried onions separate in a container on the counter. When ready to bake, add the mixture to a baking dish and top with the onions. Bake at 350° for 30-40 minutes until heated through.
Store leftovers in an airtight container in the fridge up to 3 days.
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Green Bean Casserole from Scratch
- 1 1/2 lbs fresh green beans cleaned and trimmed
- 8 ounces mushrooms sliced (button, baby bella or cremini)
- 2 onions sliced (red, yellow or white)
- 1 tsp garlic cloves grated
- 2 1/2 cups milk heavy cream, whole milk or 2%
- 1/2 cup grated parmesan cheese
- 1/2 cup shredded Gruyère cheese
- 1/2 tsp salt and 1/2 tsp black pepper
- 3 tbsp butter
- 1 tsp ground mustard powder
- 1/4 cup + 2 tbsp All purpose flour
- 1/2 cup canola or vegetable oil
- Preheat oven to 350°F.
- Bring a large pot of water to boil. Add the green beans and cook 4 minutes. Get a bowl of ice water ready. When the green beans are finished cooking remove them to the bowl of ice water to stop the cooking. Drain and set the beans aside.
- Prepare the onions: add the oil to a heavy bottom pan and heat over medium high.
- Toss the sliced onions with 1/4 cup flour. Once the oil is hot, add the onions. Cook until golden brown in color. This shouldn’t take too long so don’t walk away, they burn easily! Stir the onions to keep them moving in the oil.
- When browned, remove with a slotted spoon to drain on paper towels. Sprinkle over salt to taste while still hot. Set aside until ready to top your green bean casserole.
- Heat the butter in a large pan over medium heat. Add the mushrooms and cook until softened and the liquid has evaporated, about 5-6 minutes. Add the garlic and cook 30 seconds – 1 minute, stirring often.
- Sprinkle in 2 tablespoons of the flour evenly over the mushroom mixture, add the mustard powder, salt and pepper. Whisk and cook for 1 minute.
- Slowly pour in the milk or cream while whisking constantly over medium high heat. Continue whisking until the mixture comes to a boil and thickens, about 5 minutes.
- Remove the pan from the heat and stir in the cheese until melted. Add in the green beans and stir together until evenly coated.
- Lightly spray a 9×13 baking dish and pour in the green bean mixture. Top with the fried onions, cover with foil and bake for 30 minutes until bubbly.