Bring a large saucepan of water to the boil, then stir in the vegetable stock cube. Add the couscous to the pan and cook for 6–8 minutes until ‘al dente’, or according to the packet instructions. Drain into a large, fine sieve and cool under cold running water.
Meanwhile, quarter the tomatoes and mix with the peppers, cucumber, basil and chickpeas in a large bowl. Make the dressing by putting all the ingredients in a mini chopper or a small food processor bowl and blending until smooth.
Mix the cooled couscous with the vegetables and chickpeas, then stir in half of the dressing and toss until all the ingredients are well coated in the dressing. Season with salt and pepper, then divide into serving bowls.
Mix together the parsley and spring onions, scatter over each bowl of couscous and crumble over the feta. Serve with Mediterranean-style flatbread and the remaining dressing, if liked.