gratine

/ɡrɑːˈtiːn/
verb
  1. To cook (a dish) with a topping of breadcrumbs, cheese, or sauce until it forms a golden brown crust.
    • The chef decided to gratine the macaroni and cheese for extra crispiness.
    • You should gratine the casserole under the broiler for just a few minutes.
    • She learned to gratine vegetables to make them more appealing to her children.