Whitefish gratin with potatoes and capers

A simple, tasty dish with local Lake Garda whitefish, capers and lemons. Other fish work too, I had fillets, but boil whole fish and remove flesh if preferred.

INGREDIENTS FOR 4
5/6 WHITEFISH FILLETS, LAVARELLO
4 MEDIUM POTATOES
2 TABLESPOONS GARGNANO CAPERS
1 GARLIC CLOVE
1 BUNCH PARSLEY
1 LEMON, ZEST
4 TABLESPOONS BREADCRUMBS
SALT
PEPPER
GARDA EXTRA VIRGIN OLIVE OIL
I clean fillets and remove bones.I boil in water with salt and half the lemon zest for 5 minutes.I drain, reserving water.I peel and chop potatoes and cook in the fish water.I drain into a bowl and mash with a fork. I add fish broken by hand.I set aside and chop desalted capers.I mix capers, chopped parsley, salt, pepper and plenty of extra virgin olive oil in a small bowl.I grate remaining lemon zest.I gently mix sauce into potatoes and fish. I divide between 4 individual ovenproof dishes and sprinkle breadcrumbs.I drizzle with oil and bake at 180°C for 10 minutes.