Meanwhile, halve and seed 4 red or green peppers, then cook in boiling water for 5 minutes. Drain well and put into a grill pan, cut side up. Stir 250g diced cooked chicken and 1 tbsp chopped fresh oregano into the couscous. Season, then divide among the peppers. Top with 100g crumbled feta cheese and grill slowly, under a medium heat, for 10 minutes or until hot and golden.