By quick-blanching vibrant fresh beans and smothering them in a rich roux made with chicken stock, cream, chopped mushrooms, and freshly grated nutmeg, every bite delivers incredible depth of flavor. Topped with light, shatteringly crisp onion strings fried in a panko coating, this side dish steals the show at any Thanksgiving or dinner feast. Check out the video from RecipeTin Eats above for visual aid.
Ingredients (Serves 6 to 8 people / Yields one 9x13-inch casserole)
- The Crispy Fried Onion Topping:
- 2 large Yellow Onions (thinly sliced)
- 1/2 tsp Salt & 1/4 tsp Black Pepper
- 1/4 cup All-Purpose Flour
- 1/2 cup Panko Breadcrumbs (for extra crunch)
- Vegetable or Canola Oil (for deep frying)
- The Fresh Green Beans:
- 1.5 lbs (700g) Fresh Green Beans (trimmed and cut into 2-inch pieces)
- Large pot of boiling salted water
- The Scratch-Made Mushroom Cream Sauce:
- 4 tbsp (50g) Unsalted Butter
- 10 oz (300g) Cremini / Brown Mushrooms (finely chopped)
- 1/2 tsp Salt & 1/4 tsp Black Pepper
- 2 cloves Garlic (minced)
- 1/4 cup All-Purpose Flour
- 1 1/2 cups Chicken Stock (or vegetable stock)
- 1 cup Heavy Cream
- 1/4 tsp Freshly Grated Nutmeg
Step-by-Step Instructions
- Step 1: Make the crispy fried onions Thinly slice two large yellow onions. Place them in a large bowl and toss with 1/2 tsp salt, 1/4 tsp black pepper, 1/4 cup flour, and 1/2 cup panko breadcrumbs until well coated. Heat 1 inch of oil in a pot over medium-high heat. Fry the coated onions in batches for 3 to 4 minutes until deep golden brown and crispy. Drain on paper towels and set aside.
- Step 2: Blanch and dry the green beans Trim the stem ends of fresh green beans and cut them into 2-inch pieces. Drop into a pot of boiling salted water and cook for 3 minutes until vibrant green and tender-crisp. Drain in a colander, spread on a clean kitchen towel, and pat completely dry. (Removing moisture prevents the casserole sauce from turning watery).
- Step 3: Sauté mushrooms and garlic Melt 4 tbsp butter in a cast-iron skillet over medium-high heat. Add the finely chopped mushrooms and cook for 5 to 6 minutes until browned. Season with salt and pepper, then stir in 2 minced garlic cloves, cooking for 1 minute until fragrant.
- Step 4: Build the cream sauce roux Sprinkle 1/4 cup flour over the sautéed mushrooms and cook for 1 minute while stirring to remove the raw flour taste. Gradually pour in 1 1/2 cups chicken stock while whisking constantly to prevent lumps, followed by 1 cup heavy cream. Simmer for 3 to 4 minutes until thick and glossy. Finely grate 1/4 tsp fresh nutmeg into the sauce and stir well.
- Step 5: Toss beans with sauce and assemble Transfer the dried green beans into a large mixing pot. Pour the hot mushroom cream sauce directly over the beans and fold together until evenly coated. Scrape the mixture into a 9x13-inch ceramic casserole baking dish and level the top. Scatter the homemade crispy fried onions evenly over the surface.
- Step 6: Bake and serve hot Bake in a preheated oven at 390°F (200°C) for 18 to 20 minutes until the sauce is hot and bubbling around the edges and the onions are deeply browned. Serve piping hot as the ultimate holiday side dish!
Kitchen Gadgets & Pro Tips
- Speedy Thin Onion Slicing & Mushroom Prep: Hand-slicing whole onions into ultra-thin uniform strips and dicing mushrooms can take a lot of time and make your eyes water. A Vegetable Chopper uses sharp interchangeable stainless steel blades to slice onions paper-thin and dice mushrooms in seconds, catching all prep directly inside the built-in box for a mess-free counter.