1. Preheat the Oven: Preheat your oven to 375°F (190°C). Grease a baking dish with butter or cooking spray.
2. Blanch the Vegetables: Bring a large pot of salted water to a boil. Add the broccoli and cauliflower florets and blanch for 2-3 minutes until slightly tender. Drain and set aside.
3. Sauté Aromatics: In a skillet, heat olive oil over medium heat. Add minced garlic and chopped onion. Sauté until fragrant and translucent, about 2-3 minutes.
4. Combine Ingredients: In a large bowl, mix blanched broccoli and cauliflower with sautéed garlic and onion. Add cheddar cheese, mozzarella cheese, heavy cream, salt, pepper, and red pepper flakes (if using). Mix until well combined.
5. Transfer to Baking Dish: Transfer the mixture to the prepared baking dish. Spread it out evenly.
6. Top with Breadcrumbs: Sprinkle breadcrumbs over the top of the mixture.
7. Bake: Place the baking dish in the preheated oven. Bake for 25-30 minutes, until the cheese is melted and bubbly, and the top is golden brown.
8. Serve: Once baked, remove from the oven and let it cool for a few minutes. Garnish with chopped fresh parsley before serving.
9. Enjoy: Serve hot as a side dish or a light main course. Enjoy the creamy, cheesy goodness of this broccoli and cauliflower bake!

This flavorful bake is a delightful way to enjoy the goodness of broccoli and cauliflower. It’s creamy, cheesy, and packed with wholesome flavors that will satisfy your taste buds.