Place the cucumber slices into a sieve and sprinkle with a teaspoon of salt, leaving for 10 minutes to draw out the water. Then mix the rice vinegar with the caster sugar and stir until dissolved. Place the cucumber in the vinegar mix and stir, then leave to one side.
Place half the sunflower oil and the onion into a medium sized saucepan and sauté until soft.
Meanwhile, rinse the rice until cold running water runs clear. Once the onion is soft, add the rinsed rice to the pan and sauté for one minute. Add the coconut milk and water, bring to the boil, then reduce the heat to a low simmer, cooking for 10-15 minutes until the rice is tender.
While the rice is cooking, place the juice of 1 lime, the coriander, garlic, half the chopped chilli and the Greek yoghurt into a food processor and whizz into a pourable sauce. Season.
Coat the asparagus with the remaining oil and cut the remaining lime in half. Heat a griddle pan until searing hot and griddle the asparagus and lime until strong lines appear, then remove from the heat.
Heat the lentils as per the packet instructions and toss through the cooked rice, along with the drained cucumber.
Spoon the rice onto a large serving platter and top with the asparagus and soft-boiled eggs. Crush the California walnuts and sprinkle over the salad along with the remaining chopped chilli. Finely drizzle over the green coriander sauce and serve with the griddled lime halves on the side.