Cut the vegetables

Boil the vegetables

Melt the butter in a heavy bottomed saucepan over medium heat

Add the garlic and onions and sauté

Add the flour and whisk into the butter. Cook for 2 minutes till the flour is cooked and smells slightly nutty

Start adding milk in a steady stream while whisking continuously

Add milk in parts and keep whisking it into flour till it thickens, adding more milk as you go

Add rosemary and season with salt and pepper

Add the vegetables to the sauce

 Mix well

Pour this into a baking dish. Evenly sprinkle parmesan cheese, mozzarella cheese and panko bread crumbs on top of the vegetables

Bake for 20 minutes

And it's ready! Serve hot with some bread!