Fill a large pan with water. Sprinkle in a good pinch of salt. Pop a lid on the pan and bring to the boil.

Meanwhile, peel the onion and finely chop it. Peel and crush or finely chop the garlic cloves. Roughly chop the olives.

Pour 1 tbsp oil into a deep frying pan or wok and warm over a medium heat for 2 mins. Slide in the chopped onion and garlic. Sprinkle in 2 tsp fennel seeds and a pinch of salt and pepper. Fry for 5 mins, stirring occasionally, till the onion has started to soften.

While the onion is cooking, slice the cherry vine tomatoes in half. Slide the tomatoes into the pan and stir well. Cook for a further 5 mins, stirring every so often. Take off the heat and set aside.

While the tomatoes cook, snap the woody ends off the asparagus – bend them and they'll snap in the right place. Chop into bite-size pieces. Finely grate the zest from the lemon into a bowl and set aside.

The water in the pan should be boiling by now. Tip in the pasta. Cover and simmer for 10 mins till the penne is cooked but still has a little bite to it.

When the pasta has 5 mins remaining, slide the chopped olives and asparagus into the pan with the tomatoes. Pop back on a medium heat and warm, stirring often.

Drain the pasta, reserving 4 tbsp of the cooking water. Tip the pasta and reserved water into the frying pan with the veg. Sprinkle in the lemon zest and squeeze in half the juice. Scatter in the rocket leaves. Toss everything together over the heat, till the rocket leaves have wilted and the veg are tender.

Divide the pasta and veg between two warm bowls and serve with a crack of black pepper.