- 1/2 small red onion, cut into thin rings and separated
- 2 tablespoons all-purpose flour
- kosher salt and black pepper
- 2 1/2 tablespoons olive oil
- 8 ounces button mushrooms, sliced
- 1 cup 1 percent milk
- 1 pound frozen green beans, thawed
- In a bowl, toss the onion with 1 tablespoon of the flour and ¼ teaspoon salt. Heat 1½ tablespoons of the oil in a large skillet over medium-high heat. Cook the onion, stirring, until golden brown, 1 to 2 minutes; transfer to a plate.
- Wipe out the skillet and heat the remaining tablespoon of oil over medium-high heat. Cook mushrooms, stirring, until tender, 5 to 6 minutes.
- Reduce heat to medium. Sprinkle the remaining tablespoon of flour over the mushrooms and cook, stirring, for 1 minute. Add the milk and ¼ teaspoon each salt and pepper. Simmer, stirring, until mixture begins to thicken, 1 to 2 minutes. Add green beans and cook until heated through, 3 to 4 minutes. Top with the onions.