Heat 1 tbsp of the oil in a large non-stick frying pan set over a medium-high heat. Add half the sage leaves and fry for a minute or so on each side - or until crispy. Remove from the pan, tip onto a plate and set aside. Finely chop the remaining half of the sage leaves.
In the same pan, add the other tbsp of oil, then the onion, carrot and celery. Fry over a medium heat for about 10-15 minutes, stirring often, until softened.
Add the garlic and anchovies. Season with salt and freshly ground black pepper, then continue to fry for 5 minutes, stirring often.
Add the finely chopped sage leaves to the pan and cook for another 5 minutes, stirring often.
Add the chopped tomatoes and stock. Bring to a simmer and cook for 10 more minutes.
Add the drained chickpeas, stir well, then simmer for 10 minutes on a low heat (at this point, the sauce should have reduced slightly).
Remove from the heat and, using a hand-held stick blender, blitz half the sauce. Return to the heat and bring to the boil. Add the ditalini pasta, lower the heat slightly and cook according to packet instructions (or until al dente) - add a splash more water if needed to completely cover the pasta. Season to taste.
Divide between two bowls, season with freshly ground black pepper and garnish with the crispy sage leaves. Sprinkle with freshly grated Parmesan and drizzle with extra virgin olive oil. Enjoy!