Wash the vine leaves and blanch them in plenty of water for 3 to 4 minutes. Strain them and let them dry on a cotton cloth. For the filling: clean and wash the vegetables, then chop them into small pieces and put them in a heavy-bottomed frying pan with the slightly heated olive oil. Add salt and pepper, and stir – constantly! – while you let the chopped vegetables soften for roughly 10 minutes over a medium heat. Turn it off and leave to cool. When they’re cold, mix these vegetables in a bowl with the grated pecorino, breadcrumbs, parsley and beaten egg until you have a homogeneous mixture. Place a spoonful of filling in the centre of each leaf, then roll it up, closing it tightly (with toothpicks if you like) at the ends. Distribute a couple of spoonfuls of Sugo Bombolino (or another tomato sauce) in the bottom of a baking tray and arrange the stuffed leaves in it, one beside the other. Cover them with the remaining sauce and then add a sprinkling of grated pecorino on top. Put the baking tray in a preheated oven, at 180 °C, for 40 minutes. Halfway through the cooking time, take the tray out and baste the leaves with the juices that have formed in the bottom; if they seem too dry, add 2 spoonfuls of water as well. When they are cooked, leave them to rest for at least 15 minutes before serving.