Thaw the prawns. Peel the garlic and ginger and chop finely. Core the chilli pepper and cut into rings. Heat a little oil in each of 2 pans, then add half of the ginger, garlic, chilli pepper and turmeric to both pans. Add the prawns to a pan, fry them and then deglaze with coconut milk. Reduce and season with salt and pepper.
Prepare the rice in the other pan like a risotto, so keep adding water until it is over cooked (the rice takes about 15-20 minutes). Add the mung bean seedlings 5 minutes before the end of the cooking time and season with salt and pepper.
Arrange the rice and sauce in a deep plate and garnish with sliced red onions.