Braised French Onion Chicken with Gruyere Cheese Recipe. Bake this DELICIOUS comfort food casserole in the oven. Recipes like this are perfect for dinners and meals with rice as a quick and easy side dish. Your family will love this weeknight or weeknight supper! Comfort food like this is packed with chicken thighs, garlic, mustard, caramelized onions and lots and lots of cheese. Pretty healthy wholesome ingredients if you ask us!