Unique Green Bean Casserole Moderne

Ever since I developed this update of that sentimental favorite of yesteryear, the Green Bean Casserole, with fresh ingredients in place of the canned green beans, canned mushroom soup, and canned crispy onions, I have had a flood of requests for the recipe at this time of year. A favorite Thanksgiving side dish, my fresh version is so hearty it qualifies as a vegetarian entrée, which is why it can be found in the vegetarian chapter of Sara’s Secrets for Weeknight Meals.  I prefer the thin French green beans called haricots verts to the husky variety we grow here, but our native fatties would work just fine, as would any variety of mushroom. Serve with Cole Slaw (Sara’s Secrets for Weeknight Meals, page 38) and Sautéed Beets with Balsamic Vinegar (page 305).
Ingredients
Makes 4 to 6 servings
Hands-on time: 15 minutes
Total preparation time: 40 minutes
Kosher salt
1 large white onion, sliced (about 2 cups)
1 tablespoon vegetable oil
Freshly milled black pepper
8 ounces haricots verts or green beans, trimmed
3 tablespoons unsalted butter
2 tablespoons chopped shallots
1 garlic clove, minced (about 1 teaspoon)
12 ounces mixed shiitake and white mushrooms or any assortment of mushrooms, cleaned
2 teaspoons rinsed and dried fresh thyme or 2/3 teaspoon dried
3 tablespoons unbleached all-purpose flour
2 cups whole milk, heated
4 ounces Cheddar cheese, grated (about 1 cup)

• Bring a large pot of salted water to a boil. Preheat the broiler to high. Grease a shallow 2-quart baking dish.
• Toss the onion in a bowl with the oil, 1/4 teaspoon salt, and 1/8 teaspoon pepper. Spread the onion on a baking sheet and place under the broiler, about 5 inches from the heat source. Broil until the edges begin to brown, about 8 minutes. Set onion aside. Reduce the oven to 375°F.
• Add the haricots verts to the boiling water and cook 2 minutes; drain immediately and pat dry.
• Melt the butter in a large skillet over medium-low heat. Add the shallots and garlic and cook for 2 minutes. Discard the shiitake stems; slice the shiitake caps and white mushrooms. Turn the heat up to medium; add all the mushrooms and the thyme and cook, stirring occasionally, until most of the liquid the mushrooms give off has evaporated. Sprinkle the flour over the mushrooms and cook, stirring, 2 minutes.
• Add the milk gradually, whisking constantly. Bring the mixture to a boil and simmer for 3 minutes. Stir in the green beans and half the cheese; season with salt and pepper to taste.
• Transfer the mixture to the baking dish. Top with the remaining cheese and the broiled onion rings and bake until hot and bubbling, about 25 minutes.