01 - Set oven to 350°F and lightly grease a medium baking dish.
02 - Steam or blanch broccoli florets and carrot slices for 3–4 minutes until just tender. Drain thoroughly and set aside.
03 - In a medium saucepan over medium heat, melt 2 tablespoons butter. Whisk in the flour and cook for 1 minute. Gradually add milk, continuing to whisk until smooth and thickened.
04 - Remove pan from heat and stir in the shredded cheddar, garlic powder, onion powder, salt, and pepper. Mix until cheese is melted and sauce is creamy.
05 - Gently fold blanched broccoli and carrots into the cheese sauce, ensuring even coating. Transfer mixture to prepared baking dish.
06 - In a small mixing bowl, combine panko breadcrumbs, melted butter, and Parmesan cheese if using. Sprinkle evenly over the vegetable mixture.
07 - Bake for 25–30 minutes until the top is golden and bubbly. Allow to rest for 5 minutes before serving.