Steamed prawns with slow-roast tomato mayonnaise

You’ll end up with twice as much mayonnaise as you need for this dish, but it’s really not worth making in smaller quantities: keep the leftovers in the fridge to use with cold meat, fish or veg; it will keep for up to three days. Serves four as a first course or two as a lunch.

2½ tsp dark muscovado sugar
2cm piece fresh ginger, peeled and finely grated
2 garlic cloves, peeled and crushed
1½ tbsp olive oil
3 plum tomatoes, cut in half
Salt
24 raw tiger prawns, heads and shells on
1 egg yolk
1½ tsp Dijon mustard
2 tsp red-wine vinegar
⅛ tsp sweet smoked paprika
⅓ tsp sweet paprika
75ml sunflower oil
10g-20g bunch fresh coriander
1 lemon, quartered or halved

Heat the oven to 140C/285F/gas mark 1. Mix the sugar, ginger, garlic, olive oil and a quarter-teaspoon of salt in a bowl. Add the tomatoes, gently toss, then lay cut side up on a small, parchment-lined baking tray. Roast for two hours, turning every half-hour or so, until caramelised and starting to dry out, then set aside to cool for 10 minutes.

In the meantime, bring a steamer pot to a boil and put in half the prawns. Steam for three to five minutes, until just cooked, then remove and repeat with the other prawns. Once the cooked prawns are almost cool, cover and refrigerate.

Transfer the tomatoes (remove and discard any burnt bits) to the small bowl of a food processor and add the egg yolk, mustard, vinegar, both paprikas and a quarter-teaspoon of salt. Blitz until smooth, then, with the motor still running, slowly pour in the sunflower oil and process until the mixture takes on a mayonnaise consistency.

Arrange the prawns on a platter or a large, shallow bowl. Garnish with the coriander and lemon wedges, and serve with the sauce alongside. A large bowl of warm, lemony water on the table will help minimise the mess involved in peeling and dipping.