-
1
Place the lavarello bones and heads in a saucepan with the onion, celery, wine, bay leaves, and cold water, then bring to a bare simmer and cook for exactly 20 minutes — no longer, or the fumet turns bitter and muddy, with a chalkiness that no amount of seasoning will correct. Pass through a fine sieve without pressing, so the stock stays clear and light rather than clouded by bone sediment. Keep at a gentle simmer throughout the risotto so each ladleful enters the rice hot and does not arrest the cooking.
-
2
Melt 20 g butter in a wide, heavy saucepan over medium heat, add the chopped onion and sweat without colour until completely soft and translucent, 6–8 minutes — the onion must surrender entirely so it dissolves into the risotto rather than appearing as detectable shards against the delicate fish. The pan should be silent save for a very quiet sizzle; the moment you hear any spitting or see any browning, reduce the heat at once.
-
3
Add the Carnaroli and toast, stirring constantly, for 2 minutes until each grain is coated in butter and the rice smells faintly of warm starch — this brief toasting firms the outer surface of the grain so it can absorb the fumet gradually and hold its shape through the long cooking ahead. Every grain should be moving; any that sit still on the base will colour unevenly.
-
4
Pour in the white wine and stir until fully absorbed and the sharp alcohol smell has left the pan, because raw wine acid carried into the risotto will fight the clean, cool flavour of the lake fish throughout. Only when the smell is gentle and the pan looks nearly dry should you proceed to the fumet.
-
5
This is where the dish lives or dies. Add the hot lavarello fumet one ladleful at a time, stirring steadily and allowing each addition to be absorbed before adding the next — the fumet must be light and restrained, because a strongly flavoured stock or a sea-fish substitute will obliterate the gentle lake character the dish depends upon. Continue for 15–16 minutes until the rice is almost done: the grain offers slight resistance at its core and the risotto moves in slow, starchy waves when the pan is shaken.
-
6
Lay the lavarello fillet pieces across the surface of the risotto without stirring them in, so the fish steams above the starch rather than breaking apart in it. Cover the pan and allow the residual heat to cook the fish for 3 minutes — the fillets should be just opaque throughout and yield with the lightest pressure; do not extend this step, as overcooked freshwater fish becomes mushy and loses the clean, faintly sweet flavour that defines the dish.
-
7
Remove from the heat, add the 40 g cold butter in small pieces and the Grana Padano, folding gently so as not to break the fish — cold butter worked in off the heat binds the cooking liquid and starch into a loose, glossy cream without the risotto tightening or going heavy. The risotto should flow — all'onda — when the pan is tilted. Finish with a few drops of Gardone olive oil, taste for salt, and serve immediately.