1.MISO BROTH: Combine the ingredients into a saucepan and bring almost to the boil. Reduce heat and simmer for 20 minutes. Strain and set aside.
2.Heat the palm sugar and fish sauce in a small pan until the sugar dissolves; cool slightly.
3.Whisk the eggs in a large bowl and stir in palm sugar and fish sauce mixture.
4.Heat a little of the peanut oil in a frying pan over a medium-high heat. Pour in just enough of the egg mixture to cover the bottom of the pan. Cook until just golden on the bottom but still moist on top. Slide the omelette out onto a plate and cook another three, using the rest of the eggs.
5.Heat a little more oil in a wok and stir-fry mushrooms for 1-2 minutes. Add duck meat and cook a further 2 minutes or until hot.
6.Divide the duck mixture among 4 omelettes and top with bean sprouts and snow pea sprouts. Roll up and place into serving dish.
7.Ladle hot miso broth over the top. Drizzle with kecap manis and sprinkle with julienne green onions; serve immediately.