Skillet Butter Beans With Caramelized Onions

Preheat a 12-inch cast-iron skillet over medium-low heat, then add the oil and butter.

Add the onions and ½ teaspoon of the salt. Cook until the onions are deeply caramelized, about 50 to 60 minutes, stirring occasionally. If the onions begin to burn, reduce the heat, and remove any crispy bits if desired. If the onions appear dry, add a splash of water or additional oil. (Note that the onions can be prepped ahead of time and stored in the fridge for up to a week.)

Once the onions are caramelized, push them to one side of the skillet.

Add the mushrooms and thyme and increase the heat to medium. Cook until the mushrooms are lightly browned, about 10 to 12 minutes. Stir the onions and mushrooms separately during this window to keep them from burning.

Place an oven rack in the top third of the oven and preheat the broiler.

To the skillet, add the kale, beans, vegetable broth, and remaining 1 teaspoon of salt. Stir to combine and bring the mixture to a simmer. Cover and cook until the kale is wilted, about five minutes.

Uncover the skillet, top with freshly grated Gruyère, and place under the broiler. Broil for two to three minutes, or until the cheese is melted and golden brown. Cool before serving.

Serve with toasted sourdough or over a bed of brown rice.