A gas cooktop (105) includes a gas burner (130-133) and a grate (135-138) for supporting cookware above the gas burner (130-133). The grate (135-138) includes a removable insert (230) having an upper surface (240) and a lower surface (400) and a plurality of tines (220-227) for supporting the removable insert (230). When the lower surface (400) of the removable insert (230) is contacting the plurality of tines (220-227), the grate (135-138) supports flat-bottomed cookware on the removable insert (230) at a first height above the gas burner (130-133). When the upper surface (240) of the removable insert (230) is contacting the plurality of tines (220-227), the grate (135-138) supports flat-bottomed cookware on the removable insert (230) at a second height above the gas burner (130-133), the second height being greater than the first height. When the removable insert (230) is not contacting the plurality of tines (220-227), the grate (135-138) supports round-bottomed cookware on the plurality of tines (220-227).