Green Bean & Mushroom Gratin with Comté and Fried Shallots
- 1 cup canola oil
- ½ pound shallots (about 6 whole), peeled and very thinly sliced
- 1 ¾ teaspoons salt, divided
- 1 pound fresh green beans, trimmed
- 2 tablespoons butter
- 10 ounces fresh cremini mushrooms
- ¾ teaspoon freshly ground black pepper, divided
- 1 large garlic clove, minced
- 2 tablespoons flour
- 1 cup low-sodium chicken broth
- 1 cup whole milk
- 4 ounces Comté, shredded (about 1 cup, packed)
- Line a large plate with paper towels. In a small saucepan, heat the oil over medium-high heat until it begins to shimmer and lightly smoke. Add the shallots and cook, stirring often, until light golden brown, about 7-9 minutes. Using a slotted spoon, transfer the shallots to the paper towel-lined plate. Sprinkle with ¼ teaspoon salt.
- Preheat the oven to 400°F. Butter a 2- to 3-quart casserole dish.
- Bring a large pot of salted water to a boil. Add the green beans and cook until crisp-tender, 4-5 minutes. While the beans cook, fill a large bowl with ice water. Drain the beans and immediately plunge them into the ice water to stop cooking. Transfer to a clean kitchen towel to dry.
- In a large skillet, melt the butter over medium-high heat. Add the mushrooms and toss. Cook, stirring occasionally, until golden brown, about 5 minutes. Add 1 teaspoon salt, ½ teaspoon pepper and the minced garlic; cook 1 minute. Sprinkle in the flour and cook, stirring, 30 seconds. Whisk in the broth and milk and bring to a simmer. Cook 5-6 minutes, or until thickened. Turn off the heat and add half of the shredded Comté, along with ½ teaspoon salt and ¼ teaspoon pepper; stir until the cheese is melted. Add the green beans and stir to coat.
- Transfer the mixture to the prepared baking dish. Sprinkle the remaining Comté over the top. Bake 10 minutes. Before serving, sprinkle the fried shallots over the gratin. Serve warm.