Cook potatoes by boiling in unsalted water for approx 15 minutes, depending on the size of the pieces, until soft.
Mix together the breadcrumbs with most of the herbs.
Pre heat grill.
Drain and mash potatoes roughly with the milk and season with pepper and remaining herbs.
Spoon into an ovenware dish scatter with crumb mix.
Finish with grated cheese and grill to toast crumbs and melt cheese.