Green Bean Casserole

How to Make Green Bean Casserole

1. 1

   Step 1: Trim and blanch the green beans

   Trim the stem ends from the green beans and cut any long ones in half for even cooking. Bring a large pot of salted water to a boil, add the beans, and cook until bright green and just tender, about 3–4 minutes; immediately transfer to an ice bath to stop cooking and preserve color. Drain well and pat dry before assembling the casserole.

   For this step

   • 1 1/2 lbFresh green beans, trimmed
   
2. 2

   Step 2: Sauté aromatics and mushrooms, make the sauce

   In a large skillet over medium heat, melt the butter and add the sliced onion; cook until translucent and starting to brown, about 5–7 minutes, then add the sliced mushrooms and cook until their liquid evaporates and they begin to brown, another 4–6 minutes. Sprinkle the flour over the vegetables and cook, stirring, for 1 minute to remove the raw flour taste. Gradually whisk in the milk and chicken stock and simmer until the mixture thickens to a creamy sauce, 3–5 minutes; season to taste with salt and pepper.

   For this step

   • 4 tbspUnsalted butter
   • 1 mediumYellow onion, sliced
   • 8 ozCremini (baby bella) mushrooms, sliced
   • 3 tbspAll-purpose flour
   • 1 1/4 cupsWhole milk
   • 1/2 cupLow-sodium chicken stock (or vegetable stock)
   
3. 3

   Step 3: Combine beans with the mushroom sauce

   Fold the drained green beans into the mushroom sauce until evenly coated and adjust seasoning as needed. Transfer the mixture to a 9x13-inch (or similarly sized) baking dish, spreading it into an even layer. If making ahead, cover and refrigerate, then proceed to topping and baking when ready.
   
4. 4

   Step 4: Toast the panko topping

   In a clean skillet over medium heat, add 1–2 tablespoons of butter (from the butter used earlier) and the panko breadcrumbs and cook, stirring frequently, until the crumbs are uniformly golden and crisp, about 4–6 minutes. Remove from heat and season the crumbs with a pinch of salt and a little freshly ground black pepper; this topping will give the casserole its signature crunch.

   For this step

   • 1 cupPanko breadcrumbs
   
5. 5

   Step 5: Assemble and bake until bubbly

   Scatter the toasted panko evenly over the sauced green beans and place the dish in a 375°F (190°C) oven. Bake until the sauce is bubbling at the edges and the topping is deep golden, about 20–25 minutes. Let the casserole rest 5 minutes before serving so the sauce settles, then serve hot.
   

1. Trim the stem ends from the green beans and cut any long ones in half for even cooking. Bring a large pot of salted water to a boil, add the beans, and cook until bright green and just tender, about 3–4 minutes; immediately transfer to an ice bath to stop cooking and preserve color. Drain well and pat dry before assembling the casserole.
2. In a large skillet over medium heat, melt the butter and add the sliced onion; cook until translucent and starting to brown, about 5–7 minutes, then add the sliced mushrooms and cook until their liquid evaporates and they begin to brown, another 4–6 minutes. Sprinkle the flour over the vegetables and cook, stirring, for 1 minute to remove the raw flour taste. Gradually whisk in the milk and chicken stock and simmer until the mixture thickens to a creamy sauce, 3–5 minutes; season to taste with salt and pepper.
3. Fold the drained green beans into the mushroom sauce until evenly coated and adjust seasoning as needed. Transfer the mixture to a 9x13-inch (or similarly sized) baking dish, spreading it into an even layer. If making ahead, cover and refrigerate, then proceed to topping and baking when ready.
4. In a clean skillet over medium heat, add 1–2 tablespoons of butter (from the butter used earlier) and the panko breadcrumbs and cook, stirring frequently, until the crumbs are uniformly golden and crisp, about 4–6 minutes. Remove from heat and season the crumbs with a pinch of salt and a little freshly ground black pepper; this topping will give the casserole its signature crunch.
5. Scatter the toasted panko evenly over the sauced green beans and place the dish in a 375°F (190°C) oven. Bake until the sauce is bubbling at the edges and the topping is deep golden, about 20–25 minutes. Let the casserole rest 5 minutes before serving so the sauce settles, then serve hot.