Classic Scratch-Made Green Bean Casserole
An elevated, completely from-scratch take on the classic American holiday side dish. Featuring freshly blanched green beans, a rich and savory homemade mushroom cream sauce, and an irresistible topping of crispy, golden-fried shallots.
Equipment
- 9x13-inch baking dish
- Large pot
- Slotted spoon
- Large skillet
- Medium saucepan
- Candy/deep fry thermometer
- Paper towels
Ingredients
Crispy Fried Shallots
- 3 large Shallots — Thinly sliced
- 0.5 cup Buttermilk — Can substitute with regular milk
- 1 cup All-purpose flour — For dredging
- 1 teaspoon Kosher salt — For seasoning flour
- 0.25 teaspoon Black pepper — Freshly ground
- 2 cups Canola or peanut oil — For frying
Green Beans
- 2 lbs Fresh green beans — Trimmed and cut into 2-inch pieces
- 2 tablespoons Kosher salt — For the boiling water
Mushroom Cream Sauce
- 4 tablespoons Unsalted butter — Divided
- 1 lb Cremini mushrooms — Cleaned and sliced
- 3 cloves Garlic — Minced
- 1 tablespoon Fresh thyme — Chopped
- 0.25 cup All-purpose flour — For thickening sauce
- 1.5 cups Vegetable broth — Or chicken broth if not vegetarian
- 1 cup Heavy cream — Can use half-and-half for a lighter version
- 1 tablespoon Soy sauce — Adds deep umami flavor
- 1 teaspoon Kosher salt — To taste
- 0.5 teaspoon Black pepper — Freshly ground
Crispy Fried Shallots
| 3 large | Shallots | Thinly sliced |
| 0.5 cup | Buttermilk | Can substitute with regular milk |
| 1 cup | All-purpose flour | For dredging |
| 1 teaspoon | Kosher salt | For seasoning flour |
| 0.25 teaspoon | Black pepper | Freshly ground |
| 2 cups | Canola or peanut oil | For frying |
Green Beans
| 2 lbs | Fresh green beans | Trimmed and cut into 2-inch pieces |
| 2 tablespoons | Kosher salt | For the boiling water |
Mushroom Cream Sauce
| 4 tablespoons | Unsalted butter | Divided |
| 1 lb | Cremini mushrooms | Cleaned and sliced |
| 3 cloves | Garlic | Minced |
| 1 tablespoon | Fresh thyme | Chopped |
| 0.25 cup | All-purpose flour | For thickening sauce |
| 1.5 cups | Vegetable broth | Or chicken broth if not vegetarian |
| 1 cup | Heavy cream | Can use half-and-half for a lighter version |
| 1 tablespoon | Soy sauce | Adds deep umami flavor |
| 1 teaspoon | Kosher salt | To taste |
| 0.5 teaspoon | Black pepper | Freshly ground |
Instructions
-
Preheat your oven to 375°F (190°C) and lightly grease a 9x13-inch baking dish.
If making ahead, wait to preheat the oven until right before baking. -
Bring a large pot of water to a boil and add 2 tablespoons of kosher salt. Add the trimmed green beans and blanch for about 5 minutes until tender-crisp. Immediately drain and transfer the beans to a bowl of ice water to stop the cooking process. Drain well and set aside.
~10 minDrying the green beans thoroughly after the ice bath prevents a watery casserole. -
Prepare the crispy shallots: Toss the sliced shallots in buttermilk. In a separate bowl, whisk together the flour, salt, and pepper. Heat the frying oil in a medium saucepan to 350°F (175°C).
~5 minUse a deep-fry thermometer to monitor the oil temperature to ensure the shallots crisp up without burning. -
Working in small batches, remove the shallots from the buttermilk, letting excess drip off, and dredge in the seasoned flour. Shake off excess flour and carefully lower into the hot oil. Fry for 2-3 minutes until golden brown and crispy. Remove with a slotted spoon and drain on paper towels. Repeat until all shallots are fried.
~10 minShallots will continue to darken slightly after being removed from the oil, so pull them out when they are light golden. -
Make the mushroom sauce: In a large skillet over medium-high heat, melt 2 tablespoons of butter. Add the sliced mushrooms and cook without stirring for about 4 minutes to achieve a good sear. Stir and cook for another 4 minutes until deeply browned.
~8 minDo not salt the mushrooms initially, as salt draws out moisture and prevents browning. -
Lower the heat to medium. Add the remaining 2 tablespoons of butter, minced garlic, and chopped thyme. Cook for 1 minute until fragrant. Sprinkle the 1/4 cup of flour over the mixture and stir continuously for 1-2 minutes to cook out the raw flour taste.
~3 minThe mixture will look very thick and pasty at this stage; this is the roux that will thicken your sauce. -
Slowly whisk in the vegetable broth, breaking up any flour lumps. Whisk in the heavy cream, soy sauce, 1 teaspoon salt, and 1/2 teaspoon black pepper. Bring the mixture to a simmer, stirring frequently, until the sauce thickens enough to coat the back of a spoon (about 5 minutes). Remove from heat.
~6 minIf the sauce gets too thick, you can thin it with a splash of broth or water. -
Assemble the casserole: Add the well-drained green beans to the mushroom sauce in the skillet (or combine in a large bowl if the skillet is too small). Toss until the beans are evenly coated. Stir in exactly half of the crispy fried shallots.
~2 min -
Transfer the mixture to the prepared baking dish, spreading it into an even layer. Bake uncovered in the preheated oven for 20 minutes, or until the sauce is bubbly around the edges.
~20 min -
Remove from the oven, top evenly with the remaining crispy shallots, and bake for an additional 5 minutes to ensure the shallot topping is perfectly crisp.
~5 minWatch closely during the final 5 minutes so the shallots don't burn. -
Let the casserole rest for 10 minutes before serving. This allows the sauce to thicken slightly and makes it easier to serve.
~10 min
Tips & Storage
- To make ahead: Prepare the green beans and the mushroom sauce up to 2 days in advance and store them separately in the fridge. Assemble and bake when ready. Wait to fry the shallots until the day of serving for maximum crispiness.
- For an extra layer of flavor, consider adding 1/4 cup of grated parmesan cheese to the sauce right before tossing with the green beans.
- Be sure to thoroughly pat dry your blanched green beans to prevent your rich sauce from becoming watery during baking.
- Storage: Store leftover casserole in an airtight container in the refrigerator for up to 3 days. Reheat in a 350°F oven until warmed through. Note that the fried shallots will lose some crispiness when stored; reheating in the oven (rather than the microwave) helps restore a little texture.