
To make the chilli sauce, combine the garlic, red chilli, red wine vinegar, soft light brown sugar, light soy sauce, and dark soy sauce in a small pan. Simmer for 4–5 minutes, stirring regularly, until thick and jammy. Pour into a small heatproof bowl and set aside.
For the prawn toasts, place the king prawns in a food processor and pulse until roughly chopped. Add the garlic, coriander, spring onions, sesame oil, cornflour, 1 tablespoon of the egg white, caster sugar, and a pinch of sea salt and black pepper. Blend until well mixed but not smooth.
Spread the prawn mixture thickly onto the bread slices and sprinkle with sesame seeds, pressing them into the prawns to lightly coat.
Heat 3 tablespoons of sunflower oil in a large non-stick frying pan over low-medium heat. Cook the toasts prawn-side down for 3–4 minutes, until the prawns turn pink and are cooked through. Turn the bread over and cook for about 2 minutes more, until golden-brown and crisp.
Scatter the reserved coriander leaves and spring onion over the toasts and serve with the sweet chilli sauce or a little extra soy sauce for dipping.