Countdown to Thanksgiving: Green Bean-Chayote Squash Casserole with Fried Onion Strings

I've posted my version of green bean casserole before. It's not at all hard for me to admit that this one has it beat hands down. It's from one of Grady Spears' cowboy cookbooks and even incorporates chayote squash, an ingredient important to Latin American cuisine. If you're looking for a decadent Southwestern addition to your Turkey Day table, this is it. (And, yes, Virginia, it includes the ubiquitous fried onion strings. Although these are far better than those things from a can.)

Green Bean-Chayote Squash Casserole with Fried Onion Strings
Makes 6-8 servings.

1 pound fresh green beans, ends trimmed
1/2 pound fresh chayote squash, peeled, seeded, and julienned
2 tablespoons butter
3 tablespoons vegetable oil
1 pound bacon, diced
3/4 cup diced red onion
1/4 cup unsalted butter
1/4 cup all-purpose flour
1 3/4 cups heavy cream (I didn't say it was healthy, did I?)
Kosher salt and freshly ground pepper
1 1/2 cups grated Asiago cheese
Fried Onion Strings

Blanch the green beans and chayote in a large pot of water for 5 minutes. Remove from the heat and drain in a colander. Set aside to cool.

Meanwhile butter a 9 by 13 baking dish and set aside.

Preheat the oven to 350°. Heat the oil in a large skillet over medium heat. Add the bacon, stirring as necessary to separate the pieces so they cook evenly. Drain the grease as it accumulates so that the bacon won't be swimming in grease. When the bacon is half-cooked, add the onion and continue to cook, stirring occasionally, until the bacon is done and the onion is soft. Transfer to the buttered casserole and set aside.

In a separate pan, heat the unsalted butter over medium heat. Whisk the flour into the butter to create a roux, and cook for several minutes until the roux becomes fragrant but does not brown. Add the cream slowly while whisking to prevent lumps. Adjust the heat so that the sauce is simmering, not boiling. Add salt and pepper and cook until thickened, about 5 minutes.

Put the green beans and chayote squash into the casserole with the bacon-onion mixture and cover with white sauce. Top with the grated cheese and place in the oven to bake for 20 to 25 minutes, until the mixture is bubbling.

Remove the casserole from the oven and top with the warm, crispy, fried onion strings. Serve immediately.