Green Bean Casserole with Crispy Shallot Parmesan Topping

Ingredients

Check off each ingredient as you get it ready.

• 2 pounds fresh green beans, trimmed and cut into 2-inch pieces
• 2 tablespoons kosher salt for the blanching water
• 3 tablespoons unsalted butter
• 12 ounces cremini mushrooms, sliced 1/4 inch thick
• 1 medium shallot, finely chopped
• 3 garlic cloves, finely minced
• 1/4 cup all-purpose flour
• 2 cups low-sodium vegetable or chicken stock, room temperature
• 1 cup half-and-half, room temperature
• 2 teaspoons soy sauce
• 1 teaspoon fresh thyme leaves or 1/2 teaspoon dried thyme
• 3/4 teaspoon kosher salt, plus more after tasting
• 1/2 teaspoon black pepper
• 2 medium shallots, halved and very thinly sliced
• 1 cup panko breadcrumbs
• 1/2 cup finely grated Parmesan cheese
• 3 tablespoons olive oil
• 1/4 teaspoon kosher salt for the topping
• 1/4 teaspoon black pepper for the topping

Ingredient notes

Cut the beans to a similar size so they cook evenly. Brown the mushrooms in a wide skillet; crowding traps steam. Soy sauce deepens the mushroom flavor without making the casserole taste like soy sauce. Panko gives the topping a lighter crunch than fine breadcrumbs.

How to make it

1. Heat the oven to 375°F. Grease a 9×13-inch or 3-quart baking dish.

2. Bring a large pot of water to a rolling boil and add 2 tablespoons kosher salt. Add the green beans and cook for 4 minutes, until bright green and just beginning to soften. Drain immediately, rinse under very cold water until cool and drain thoroughly.

3. Toss the sliced topping shallots, panko, Parmesan, olive oil, 1/4 teaspoon salt and 1/4 teaspoon pepper. Spread on a parchment-lined sheet pan and bake for 8–12 minutes, stirring once, until the crumbs are golden and the shallot edges are crisp. Set aside.

4. Melt the butter in a large deep skillet over medium-high heat. Add the mushrooms in an even layer and cook without stirring for 3 minutes. Continue cooking, stirring occasionally, until deeply browned and their liquid has evaporated, 6–8 minutes more.

5. Add the chopped shallot and cook for 2 minutes. Add the garlic and cook for 30 seconds, just until fragrant.

6. Sprinkle the flour over the mushrooms and stir constantly for 1 minute. Slowly pour in the stock while scraping the skillet, then whisk in the half-and-half.

7. Add the soy sauce, thyme, 3/4 teaspoon salt and 1/2 teaspoon pepper. Simmer gently for 4–6 minutes, stirring often, until the sauce coats the back of a spoon.

8. Remove from the heat. Taste and adjust the salt, then fold in the well-drained green beans. Transfer to the baking dish.

9. Bake uncovered for 18–22 minutes, until the sauce bubbles around the edges. Scatter the toasted topping evenly over the casserole and bake 5 minutes more.

10. Rest for 10 minutes before serving so the sauce settles around the beans.

Variations & substitutions

• Mushroom-free: Replace mushrooms with 2 cups thinly sliced leeks and use vegetable stock.
• Shortcut topping: Replace the homemade topping with 1 1/2 cups store-bought crispy fried onions during the final 5 minutes.
• Richer sauce: Replace half-and-half with heavy cream.
• Bacon option: Fold in 4 slices crisp cooked bacon before baking and reduce salt after tasting.

What to serve with it

• Serve with roast turkey, mashed potatoes and bright cranberry sauce.
• For a smaller meal, pair with roast chicken and a crisp salad.

Storage & reheating

• Refrigerate leftovers in shallow covered containers within 2 hours and use within 3–4 days. Reheat portions or the covered casserole to 165°F. Refresh the surface with reserved toasted crumbs after reheating if available.