pop a pan of salted water on to boil
Cook risoni in boiling water for 7 minutes or until al dente. Drain.
Heat oil in a large, deep frying pan over a medium to high heat. Add onion and garlic. Cook, stirring occasionally until soft. Add fennel. Cook, stirring for 1 minute.
Add vegetables. Cook, stirring occasionally, for about 12-15 minutes, or until tender. Add diced tomatoes and stir until hot.
Transfer to a serving bowl with risoni and basil. Stir to combine. Serve with parmesan and scatter with basil.