Here's CI's recipe. I think using the shallots is brilliant. They also have a lite version that uses porcini's and olive oil to replace the butter, etc. I can post that one too if you don't have access to it.
EXPORTED FROM LIVING COOKBOOK
CLASSIC GREEN BEAN CASSEROLE Servings: 12 Yield: 10-12 servings
The components of the casserole can be prepared ahead of time. Store the bread-crumb topping in an airtight container in the refrigerator and combine with the onions just before cooking. Combine the beans and cooled sauce in a baking dish, cover with plastic wrap, and refrigerate for up to 24 hours. To serve, remove the plastic wrap and heat the casserole in a 425°F oven for 10 minutes, then add the topping and bake as directed. This recipe can be halved and baked in a 2 qt. (or 8" square) baking dish. If making a half batch, reduce the cooking time of the sauce in step 3 to about 6 minutes (1¾ cups) and the baking time in step 4 to 10 minutes.
Oven Temperature: 425°F
Preparation Time: 30 minutes Cooking Time: 45 minutes Total Time: 1 hour and 15 minutes
TOPPING:
4 slices white sandwich bread
2 TBS. unsalted butter, softened
1/2 tsp. Kosher Salt (Diamond)
1/8 tsp. ground black pepper
3 cups canned fried onions (about 6 oz.)
BEANS AND SAUCE:
4½ TBS. kosher salt (Diamond)
2 lbs. green beans
3 TBS. unsalted butter
1 lbs. white button mushrooms
1 TBS. garlic, minced or pressed through garlic press (about 3 med. cloves)
Ground black pepper
3 TBS. unbleached all-purpose flour
1½ cups low-sodium chicken broth
1½ cups heavy cream
TOPPING:
Tear each bread slice into quarters
Pulse bread, butter, salt, and pepper in food processor until mixture resembles coarse crumbs, about ten 1 second pulses. Transfer to large bowl and toss with onions; set aside.
BEANS AND SAUCE:
Trim mushroom stems, wipe clean, and break into ½" pieces
Line up about 8 beans in a row on a cutting board. Trim about ½" from each end, then cut the beans in half.
Adjust oven rack to middle position and heat oven to 425°F. Fill large bowl with ice water. Bring 4 qts. water to boil in large Dutch oven. Add 4 TBS. kosher salt and beans. Cook beans until bright green and crisp-tender, about 6 minutes. Drain beans in colander and plunge immediately into ice water to stop cooking. Spread beans on paper-towel-lined baking sheet to drain.
Add butter to now-empty Dutch oven and melt over medium-high heat until foaming subsides. Add mushrooms, garlic, 1½ tsps. kosher salt, and ⅛ tsp. pepper; cook until mushrooms release moisture and liquid evaporates, about 6 minutes. Add flour and cook for 1 minute, stirring constantly. Stir in broth and bring to simmer, stirring constantly. Add cream, reduce heat to medium, and simmer until sauce is thickened and reduced to 3½ cups, about 12 minutes. Season with salt and pepper to taste.
Add green beans to sauce and stir until evenly coated. Arrange in even layer in 3 qt. (or 13" X 9") baking dish. Sprinkle with topping and bake until top is golden brown and sauce is bubbling around edges, about 15 minutes. Serve immediately.
Recipe Type: Casserole, Cooks Illustrated, Make-Ahead, Side Dish, Vegetables
Source: Cooks Illustrated 11/2006
Web Page:
http://www.cooksillustrated.com/recipes ... docid=7820
