Preheat your oven to 200°C/Fan 180°C/Gas 6. Trim the root and any woody ends from the fennel (saving any whispy fronds if it has any). Halve the fennel lengthways and cut into 1cm thick slices. Halve the cherry tomatoes. Peel the red onion and cut into thin wedges. Trim the courgette and cut into bite-size pieces.

Scatter the chopped veg into two roasting tins. Tuck the whole chilli into one of them. Toss the veg with 1 tbsp oil and a pinch of salt and pepper. Slide the veg into the oven and roast for 30 mins, turning halfway, till tender.

Meanwhile, warm a dry frying pan to a mediumhigh heat. Scatter in the cashew nuts and fry for 2-3 mins, stirring frequently, till golden and toasted. Tip the nuts into a bowl and allow to cool slightly.

Peel the garlic clove and crush or finely grate. Slide the garlic into a food processor (see our tip if you don't have a food processor handy) along with the toasted cashews, parsley and half of the rocket. Grate in the lemon zest and squeeze in the juice. Pour in 2 tbsp oil and sprinkle in a pinch of salt and pepper. Whizz into a pesto.

Fill a large pan with boiling water. Sprinkle in a good pinch of salt. When the water is boiling, add the spaghetti. Cook for 9 mins, till tender but retaining a slight bite. Drain the pasta through a sieve, keeping 1 cup of the cooking water.

When the veg are cooked, remove them from the oven. Finely chop the chilli.

Tip the spaghetti into a large bowl and spoon over the pesto, chopped chilli and roasted veg. Stir in a little of the pasta cooking water to loosen up the sauce a little.

Taste the pesto spaghetti and add more salt and pepper if needed. Pile onto warm plates and finish with a scattering of the remaining rocket leaves.