Cheesy Mushroom and Spinach Bake

Preheat your oven to 400 degrees F (200 degrees C). Grease a 2-quart baking dish with 1 tablespoon of olive oil.

Heat the remaining 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. Stir in the baby spinach and cook until wilted, about 2 minutes. Remove from heat.

Transfer the mushroom and spinach mixture to the prepared baking dish. Sprinkle it with the shredded aged gruyere cheese.

In a small bowl, combine the panko breadcrumbs and melted unsalted butter. Evenly spread the breadcrumb mixture over the cheese layer.

Bake the casserole until hot, bubbly, and the breadcrumbs are golden brown, about 15-20 minutes. Sprinkle with dried parsley and serve hot.