Preheat oven to 180oC and line two baking trays with baking paper.
Cut beetroot and onion into wedges and combine with olive oil, vinegar, salt and pepper. There is no need to peel the beetroot.
Place on baking tray.
Roast for 40 minutes, stirring halfway through cooking. The beetroot is cooked when it can easily be pierced with a fork.
While the beetroot is cooking, place barley in a pan with water or stock and bring to a boil.
Lower the temperature and leave the barley to cook on low, with a lid on.
Cook barley until tender and liquid absorbed, about 30-40 minutes. It will still have a ‘nutty’ texture when cooked.
Once the barley is cooked, drain any excess liquid from the barley and combine with lemon juice, olive oil and a pinch of salt if cooked in water.
Place spinach or rocket on a large serving plate. Sprinkle with barley, then beetroot, pumpkin seeds, feta and capers. Drizzle with balsamic vinegar. Enjoy.