Place the bread in a small bowl, cover with the milk and leave to soak for 10 minutes. Squeeze out the excess milk and place the bread in a large bowl, crumbling it with your fingers. Add the mince, garlic, egg, herbs, anchovies, chilli and half of the onion. Season, then mix with your hands, squeezing so everything is well incorporated. Cover and rest in the fridge for 30 minutes.
Roll the meat into golf ball–sized balls, about 30 g each. Heat half of the olive oil in a frying pan over a medium heat and brown the meatballs in batches.
Meanwhile, bring a saucepan of water to the boil. Add the broad beans, boil for a few minutes, then drain (keep the water) and set aside to cool. Peel off and discard the outer layer of the beans. Bring the water to the boil again and blanch the peas. Drain.
Heat the remaining olive oil in large frying pan over a low heat and gently fry the remaining onion with a pinch of salt for 10 minutes, or until soft and fragrant. Add the extra garlic, the browned meatballs and the chicken stock and simmer for 15 minutes. Add the broad beans, peas and lemon juice and stir to coat. Serve with a generous scattering of grated pecorino and the extra herbs.