Colorful, autumnal root vegetables come together in this cheesy, indulgent gratin. We added our aged cheddar granola as the crumble topping instead of using breadcrumbs to provide a buttery crunch, with a subtle hint of honey.
For the topping:
For the gratin:
Preheat oven to 425° F. Alternate vegetable slices by color and place in four small buttered cast iron dishes, or just one large baking dish. Season with salt and pepper.
In a bowl, mix the cheddar granola, flour, gruyere, and thyme leaves, seasoning with a little bit of salt and pepper. Set aside.
Bring cream, broth, thyme sprigs, smashed garlics, and 1 tbsp of butter to a simmer in a medium saucepan over medium heat. Season with salt and pepper. Remove from heat, cover, and let sit 10 minutes, then discard thyme and garlic.
Pour cream mixture over the vegetables in the baking dishes; place a piece of parchment paper directly on top of gratin. Bake until vegetables are tender when pierced with a fork and cream is thickened, 50–60 minutes.
Uncover, top with cheddar crumble mixture, and bake until gratin is bubbling and crumble is brown, about 15–20 minutes. You can even broil it a little. Let sit 10 minutes before serving.