Preheat the oven: Preheat your oven to 375°F (190°C). Grease a 9×13-inch casserole dish or a similarly sized baking dish.
Prepare the vegetables: Heat olive oil or butter in a skillet over medium heat. Add the chopped vegetables (such as carrots, broccoli, bell peppers, zucchini) and sauté for about 5 minutes, until slightly softened. Stir in the minced garlic and cook for another minute. Set aside.
Prepare the potatoes and onion: Thinly slice the potatoes and onion. You can use a mandoline slicer to ensure even, thin slices.
Layer the casserole:
Spread half of the sliced potatoes evenly in the greased casserole dish.
Sprinkle with salt, pepper, and dried thyme.
Add a layer of half the sautéed vegetables and onion slices.
Sprinkle ¾ cup of shredded cheese over the vegetables.
Repeat with the remaining potatoes, vegetables, and cheese, ending with a layer of shredded cheese on top.
Add the cream: Pour the heavy cream or half-and-half evenly over the casserole. This will create a creamy base as it bakes.
Optional topping: If you want a crispy topping, mix the breadcrumbs or panko with melted butter and shredded cheese. Sprinkle this over the top layer of cheese.
Bake: Cover the casserole with foil and bake in the preheated oven for 40-45 minutes. Remove the foil and bake for an additional 15-20 minutes, or until the top is golden and the potatoes are tender when pierced with a fork.
Cool and serve: Let the casserole cool for 5-10 minutes before serving to allow it to set. Serve it as a main dish or a hearty side.
Tips:
You can customize the vegetables based on what you have available. Mushrooms, spinach, and cauliflower also work great.
For a smoky flavor, consider adding a bit of smoked paprika or using a smoked cheese like gouda.
If you prefer a lighter version, you can substitute the heavy cream with milk or a plant-based alternative.
