- For the pesto, combine all the ingredients to make a paste. Season to taste with salt and pepper.
- Wash the spring onions and cut 5mm strips. Heat olive oil in a frying pan, add spring onions and peas and fry over medium heat for 10 minutes, stirring occasionally.
- Add the vegetable stock and 100g of pesto and bring to the boil and then simmer for 5 minutes. Season to taste with salt and pepper.
- In the meantime, boil the penne in salted water until al dente, drain well and add to the sauce. Let everything simmer again briefly and serve.