▢2 teaspoons Diamond Crystal kosher salt or 1 teaspoon of fine salt
▢1 cup onions chopped
▢1 tablespoon fresh garlic minced
▢½ teaspoon black pepper
▢½ teaspoon dried thyme
▢1 cup Gruyere cheese shredded
▢1 teaspoon dried parsley for garnish
Instructions
Preheat your oven to 400 degrees F. Grease a 2-quart baking dish with olive oil.
Heat the olive oil in a large, deep skillet over medium-high heat. Add the mushrooms, onions, and kosher salt. Cook, stirring occasionally, until the mushrooms have released their liquid and the liquids have mostly evaporated, about 10 minutes.
Add the garlic, black pepper, and thyme. Cook, stirring, for one more minute. Remove from heat.
Transfer the mixture to the prepared baking dish. Sprinkle it with the shredded cheese.
Bake the casserole until hot and bubbly, about 15 minutes. Sprinkle with parsley and serve.