1. Heat olive oil in a large heavy-bottomed stockpot,add celery,leeks,carrots and garlic. Cook over gentle heat for 10 minutes.
2. Add potatoes and water or stock and bring to the boil,skimming surface if necessary. Lower heat,add salt and pepper and simmer,partly covered,for 20 minutes.
3. Cook pasta in a pot of simmering salted water until al dente,then drain.
4. Add tomatoes,tomato paste,beans and silverbeet leaves to soup and simmer 10 minutes.
5. Add zucchini and simmer for 10 minutes or until the soup is nice and thick (mash a few of the beans to thicken it further). Add pasta and heat through.
6. Serve in warm pasta bowls and top with a spoonful of pesto,grated parmesan and extra pepper.
Tip Jamie Oliver suggests using up all those half-used bags of pasta at the back of your cupboard.
This is one of Jill Dupleix's 10 recipes everyone should master.