Heat your oven to 200°C/Fan 180°C/Gas 6. Chop the leaves and stalks off the carrots. Set the leaves to one side. Scrub the carrots and beetroot. Slice the beetroot into 1cm-thick rounds. Cut the carrots in half lengthways.

Drizzle over 1 tbsp olive oil and add a pinch of salt and pepper. Toss together. Drop on the garlic cloves, unpeeled. Roast for 35-40 mins till tender and caramelised.

While the veg roast, tip the barley into a pan. Cover with 500ml boiling water. Pop on a lid. Simmer for 20 mins till just tender. Drain, tip back into the pan and leave to cool.

While the barley cooks, peel and thinly slice the onion. Zest and juice the orange and lemon into a bowl. Whisk in 2 tbsp honey and season. Add the onion and toss to coat. Leave to ‘pickle’.

When the veg have roasted for 30 mins, set a griddle or frying pan on a high heat. Toss the chicken fillets with ½ tbsp olive oil and a pinch of salt and pepper. Place them in the pan and cook for 4-5 mins on each side till cooked through. Scatter over 2 tsp black onion seeds and cook for a further 1 min. Place them on a plate.

Halve the avocado and scoop out the flesh, discarding the stone. Slice into quarters. Wash a small handful of the carrot leaves. Finely shred them. Spoon the onions into the barley, leaving most of the citrus juice in the bowl. Add the carrot leaves. Stir together, taste and season.

Pluck the garlic from the veg tray and squeeze out the flesh. Stir it into the reserved citrus marinade. Add the chicken fillets and stir to coat them.

Arrange the watercress on a serving platter or a couple of plates. Pile on the barley, roast veg and the chicken. Pour over the citrus dressing. Finish with the avocado quarters and serve.