Grilled salmon with chilli glaze & lime crème fraîche

INGREDIENTS

• 6 garlic cloves , unpeeled
• 1 small onion , cut into thick slices
• 1 ancho chilli or large red dried chilli, deseeded and trimmed
• 4 tbsp soft brown sugar
• 4 tbsp cider vinegar
• 4 x 150g skinless salmon fillets
• 1 lime , zested, then cut into wedges
• 200g crème fraîche or soured cream
• chopped coriander , to serve (optional)