grilled (gruyere) cheese with mushrooms + thyme

Grilled cheese sandwiches are one of the ultimate comfort foods in my book. Buttery. Cheesy. Gooey. Crispy. Yum! Taking note from The American Grilled Cheese Kitchen in San Francisco, I recreated one of my favorites from the menu- Mushroom Gruyere. Nutty gruyere with rich mushroom umami?!? Heavenly!