Lamb tagine with giant couscous

Name: Lamb tagine with giant couscous
Ingredients: 2 aubergines, roughly chopped; 2 courgettes, cut into rings; 11⁄2 tbsp oil; 1 yellow pepper, deseeded and roughly chopped; 1 orange pepper, deseeded and roughly chopped; 6 vine tomatoes, quartered; 2 preserved lemons, diced; 300 g (11oz) giant cous cous; 1-11⁄2 tsp harissa paste; Fresh mint, finely chopped; 100 g (31⁄2oz) feta; 75 mL (3fl oz) natural yogurt; 500 g (1lb 2oz) lamb neck fillet; 1 tbsp. ground coriander; 1 tbsp. ground cumin; Pomegranate seeds, optional, to decorate