Preheat the oven: Preheat to 375°F (190°C). Grease a casserole dish lightly.
Prepare the vegetables: In a large skillet, heat olive oil or butter over medium heat. Sauté onion and garlic for 2–3 minutes until fragrant. Add zucchini, carrots, and mushrooms, cooking for another 5 minutes.
Blanch broccoli and cauliflower: Bring a pot of salted water to a boil. Add broccoli and cauliflower florets and cook for 2–3 minutes until slightly tender. Drain and combine with sautéed vegetables.
Assemble the casserole: Transfer the vegetable mixture into the greased casserole dish. Season with salt, pepper, and herbs. Sprinkle shredded cheese evenly on top.
Bake: Bake for 20–25 minutes, until the cheese is melted and golden brown. Serve warm.
Serving and Storage Tips
