Breaded Sardines with Jalapeño Yogurt and Sweet Potato, Rocket & Pickled Red Onion Salad from Fish for Dinner

16 sardines, descaled, gutted and butterflied

200g (7oz) stale seeded bread

2 teaspoons ground coriander

½ teaspoon cayenne pepper

1 teaspoon garlic powder

1 teaspoon dried thyme

2 eggs, beaten with 2 tablespoons milk

100g (3½oz) plain (all-purpose) flour

Sunflower oil, for deep-frying

2 limes, zested and halved, to serve

For the salad

2 large sweet potatoes, scrubbed

2 tablespoons rock salt

1 large or 2 medium red onions, finely sliced into rings

100ml (31/2fl oz) white wine

100ml (31/2fl oz) white wine vinegar

100ml (31/2fl oz) water

75g (2½oz) caster (superfine) sugar

2 tablespoons roughly chopped coriander (cilantro)

200g (7oz) rocket (arugula) leaves

4 tablespoons olive oil

Sea salt and freshly ground black pepper

For the yogurt

300ml (10½fl oz) full-fat Greek yogurt

3 heaped teaspoons sliced jalapeños in brine or vinegar

2 tablespoons chopped coriander (cilantro)

First make the salad. Preheat the oven to 200ºC Fan (425ºF), Gas Mark 7. Place the sweet potatoes on a baking tray on 1 tablespoon piles of rock salt and bake in the oven for 1 hour until soft inside.

Meanwhile, pickle the red onions. Place the wine, vinegar, measured water and sugar in a pan and bring to the boil. Place the red onions in a bowl and, when the pickling liquid is boiling, pour it over them. Ensure everything is submerged, then set aside to cool.

To make the yogurt, place all the ingredients in a small food processor and blitz for 1 minute. Season with salt and pepper and set aside. For the breadcrumbs, place the bread, spices, garlic powder and dried thyme in a food processor and blend to a fine crumb. Pour out into a bowl.

To finish the salad, peel the sweet potatoes, cut them into rough chunks, then place in a bowl. Drain the red onion into another bowl, reserving 4 tablespoons of the pickling liquid. Add the red onion to the sweet potato and mix with the coriander (cilantro) and rocket (arugula). Season with salt and pepper and mix well. In a smaller bowl, add the olive oil to the reserved pickling liquid and mix well; this is your dressing.

To breadcrumb the sardines, set up 3 bowls; one with the beaten egg, one with the flour and one with the breadcrumbs. Pass the butterflied sardines first through the flour, then the beaten eggs and finally the breadcrumbs and lay them onto a tray until ready to cook.

Preheat your deep-fat fryer or fill a heavy-based pan two-thirds full with oil and heat to 180ºC (350ºF). In 2 batches, fry the sardines for 2 minutes until crispy, then drain on kitchen paper and season with salt.

To serve, dress the salad with the dressing and share between 4 plates. Add the fried sardines and finish with a good dollop of yogurt and some lime zest and halves. Serve immediately.