Preheat your oven to 200°C/Fan 180°C/Gas 6. Halve the butternut squash and scoop out the seeds. Cut each half into 6-8 wedges and lay them on a baking tray (no need to peel unless you want to). Halve the tomatoes and pop them on the tray. Drizzle over 2 tbsp olive oil and dust with salt and pepper. Slide into the oven to roast for 30 mins.

While the veg is roasting, fill your kettle and boil it. Tip the barley into a pan with a pinch of salt. Cover with boiling water. Simmer for 15-20 mins till the barley is tender but still with a little bite. Drain and shake dry.

Meanwhile, zest the lemon and set to one side. Pop the pesto into a small bowl. Add 1 tbsp olive oil and squeeze in the juice from half the lemon. Whisk together to make a dressing.

When the veg has cooked for 30 mins, remove the tray from the oven. Scatter over the pine nuts and pop back into the oven for 5 mins. The pine nuts will brown and the veg will be tender.

When the squash is ready, remove it from the oven and leave to cool slightly. Arrange the watercress on a platter. Add the pearl barley and toss with half of the pesto dressing. Top with the roasted squash wedges and tomatoes. Drizzle over the remaining pesto dressing and serve with the zested lemon, cut into wedges for squeezing.