Roasted chump of lamb with rustic ratatouille

INGREDIENTS

• 25ml/1fl oz olive oil
• 25g/1oz butter
• 2 chumps
• salt and freshly ground black pepper
• 1 red onion
• 1 large aubergine
• 1 yellow pepper
• 1 red pepper
• 2 courgettes
• 1 small fennel
• 1 garlic
• 150ml/5fl oz olive oil
• 225g/8oz cherry tomatoes
• 1 tbsp roughly chopped fresh basil