Fry the spring onions gently in half of the butter until soft.
Add the rice and toast the grains thoroughly until crackling dry.
Deglaze the pan with wine and stir until the alcohol evaporates.
Submerge the rice with three ladles of hot stock and stir until absorbed.
Continue adding stock one ladle at a time, stirring constantly between additions.
Cook for about 20 minutes until the rice is creamy yet chewy.
Remove from heat and stir in the shredded lettuce to wilt.
Mix in the remaining butter and parmigiano, seasoning with salt and pepper.
Cover and rest for 4 minutes before serving on warmed plates.