Thai mackerel & sweet potato traybake

Serve mackerel in a traybake packed with sweet potato, red peppers and plenty of Thai flavours to make this healthy Asian-inspired supper

2 red chillies, deseeded and roughly chopped, plus extra sliced chillies to serve
4 shallots, roughly chopped
2 garlic cloves
1 thumb-sized piece ginger, peeled and chopped
1 lemongrass stalk
1 tbsp hot smoked paprika
2 limes, zested and juiced, plus wedges to serve
200g sweet potato, peeled and cut into 1cm cubes
1 tbsp rapeseed oil
2 red peppers, deseeded and sliced
3 dried kaffir lime leaves
4 raw mackerel fillets
4 spring onions, trimmed and sliced
small bunch coriander, chopped
320g broccoli, steamed, to serve

Put the chillies, shallots, garlic cloves, ginger, lemongrass, paprika, lime zest and juice and 1 tbsp water into a small food processor and blitz to a smooth paste.
Heat oven to 200C/180C fan/gas 6. Put the sweet potato in a large roasting tin and toss with the oil. Add the curry paste, peppers and kaffir lime leaves and roast for 35-40 mins until the potato is tender. Heat the grill to high.
Slash the mackerel skin a few times with a sharp knife. Arrange the fish over the veg, skin-side up, then grill for 4-5 mins until the skin is blistered and the flesh is cooked through.
Scatter over the spring onions, coriander and extra chillies, then squeeze over the lime wedges. Serve with the steamed broccoli.