Cook the spaghetti following pack instructions. Meanwhile, heat the oil in a frying pan and fry the garlic and pancetta until crisp, then add the chicken strips and fry briefly until they're just cooked through. Fish out the garlic clove and discard it. Beat the eggs with the grana padano and some black pepper.

Add a couple of tablespoons of pasta water to the pancetta pan along with the butter, then drain the pasta and add it to the pan. Pour in the egg mixture, take the pan off the heat and toss together so the egg cooks in the heat of the pasta. Divide between four warm bowls and top with more cheese, if you like.