Tomato, Feta and Orzo Soup

Ingredients

• 1 onion (peeled and diced)
• 800 g tinned chopped tomatoes ((2 x 400g tins))
• 1 vegetable stock cube made up with 800ml boiling water ((3½ cups))
• 4 cloves of garlic (peeled and crushed)
• ½ tsp dried oregano
• 1 tbsp balsamic vinegar
• low-calorie cooking spray
• 100 g orzo
• 100 g reduced-fat feta (crumbled)
• freshly ground black pepper