Green Bean Casserole from Scratch

Servings 6 -8 servings
I love traditional Thanksgiving dishes but couldn’t bring myself to serve something made with frozen green beans and canned cream of mushroom soup at my Thanksgiving dinner. So I developed this recipe with all fresh ingredients instead. Although it may seem like a lot of work (and it is!), the results taste better than you could possibly imagine. And since you’re likely to make this dish for special occasions, why not go all out? To make things easier, the components can be made a day or two ahead, and the whole casserole can be assembled a day in advance. You can double or triple it with no problems.
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green bean casserole


Fried onion rings:

  • 2 large yellow onions, peeled and cut into ¼-inch-thick slices (about 4 cups)
  • 4 ¼ cups whole milk, or more to cover the onions if necessary
  • 1 cup all-purpose flour
  • 1 teaspoon garlic salt
  • ¼ teaspoon salt
  • ¼ teaspoon black pepper
  • 6 cups (1 1/2 quarts) vegetable oil, for frying Approximately

Green beans:

  • 1 ½ teaspoons salt (divided), plus more for salting blanching water
  • 2 pounds fresh green beans,stem end trimmed, left whole or cut in half crosswise (about 8 cups)
  • 6 Tablespoons unsalted butter (divided)
  • ¼ cup all-purpose flour
  • 1 pound sliced button mushrooms (about 3 cups)
  • ½ teaspoon freshly ground black pepper (divided)


To make onion rings:

  • Put half the onion rings in a bowl and cover with milk. Refrigerate for at least 10minutes. (You have to fry the onions in batches anyway. By soaking only half the onions, you don’t need to use as much milk to cover them.)
  • In a medium bowl, mix the flour, garlic salt, salt and pepper. 
  • Place a deep fryer at the back of your counter, or set a large, deep, heavy-bottomed pot on the stove with the handle turned toward the wall to reduce the risk of bumping it and spilling the dangerously hot oil.Fill the fryer with the cooking oil according to manufacturer's instructions.If using a pot, fill it half full with oil. Heat the oil to 375 degrees. (Check the temperature with a deep fat/candy thermometer.  If you don’t have one, test it with a piece of bread. When the oil is hot enough, the bread will immediately float to the surface and be surrounded by bubbles.
    LOVE NOTE: The proper temperature is very important when deep fat frying. If the oil is too hot,whatever you are frying might turn dark brown before the inside is cooked through. If the oil is too cool, it will end up soggy instead of crispy. I highly recommend investing in at least two thermometers – an instant-read to check the doneness of meats and fish, and a deep fat/candy thermometer for frying and dessert-making. You can reuse frying oil a few times
  • Strain the milk from onions into a large (more than 4 cup) measuring cup and set aside (you will use this milk to soak the remaining onions and to make the sauce for the casserole). Working with a few rings at a time
    LOVE NOTE: If you try to coat too many onions at a time, they will get gummy and stick together. Coat just enough for one batch, fry them, and repeat.
    coat them evenly with the flour mixture, then place them the hot oil. As they cook, move and separate them with a two-prong fork or tongs so they don’t stick together. When the onions are golden brown and crispy, lift them from the oil with a slotted spoon or tongs and put them on paper towels to drain. While you fry these onions, soak the remaining half of the onions. Repeat the frying procedure (and be sure to save the milk).

To make the green beans:

  • Bring a large pot of water to a boil. Season generously with salt (it should taste like the sea). Set a bowl of ice water near the stove. Add the beans to the boiling water (make sure you do not overcrowd the beans, otherwise they will turn gray. Cook them in separate batches, if necessary). Cook until just tender, about 4 minutes. Remove with a slotted spoon and plunge into the ice water to stop the cooking. When cooled, strain and set aside.
  • Check the amount of reserved milk from the onions. You should have 4 cups. (You may have to either remove some or add more to equal this amount.)  
  • In a heavy-bottomed medium (4- to 6-quart) saucepan, melt 4 tablespoons of the butter over medium heat. Add flour and mix well with a wooden spoon to make a roux.  Cook, stirring frequently, until the mixture is pale yellow and resembles fine wet sand, about 5 minutes. Whisk the milk into the roux a little at a time, allowing the roux to absorb the liquid before adding more. This will help avoid lumps. Bring the mixture to a boil, then lower the heat and simmer, stirring occasionally with a wooden spoon, until it has thickened, about 15 to 20 minutes. Remove from heat, season with salt and pepper, and set aside.
  • Place a large (12- to 14-inch) skillet over high heat for several minutes. When hot, add the remaining 2 tablespoons of butter and immediately follow with the sliced mushrooms (even before the butter has completely melted. The butter will continue to melt, and adding the mushrooms right away keeps you from burning it).Sauté the mushrooms over high heat until lightly browned, about 5 to 7 minutes (you need to leave them alone to sear, but also stir occasionally so they cook evenly). Season with 1 teaspoon salt and ¼ teaspoon black pepper.
  • Stir the milk mixture into the pan with the mushrooms. Reduce heat to medium and cook for 5 minutes to blend the flavors.  Season with 1/2 teaspoon salt and ¼ teaspoon black pepper.

To assemble casserole:

  • Preheat the oven to 350°F. Butter the inside of a large casserole dish or 9x13x2-inch baking dish.
  • In a large mixing bowl, mix the green beans with the mushroom sauce and 1 cup of the onion rings. Taste for seasoning, adding salt and pepper, if necessary.
  • Scrape the green bean mixture into pan and top with the remaining fried onion rings. Bake for about 35to 45 minutes, or until hot and bubbly around the edges, and serve.