1.
To make the dressing, combine lime juice, fish sauce, sugar and chilli in a bowl. Set aside.
2.
Heat 1 tbs oil in a non-stick frypan over medium-high heat. Add the mushrooms and cook, stirring, for 4-5 minutes until golden. Set aside. Wipe the pan clean with paper towel.
3.
Beat the eggs and turmeric in a bowl. Season. Return pan to medium-high heat and add 2 tsp oil. Add half the egg mixture and swirl to coat the pan. Cook for 1 minute or until almost set, then place half the mushrooms in the centre and fold over to form a half-circle. Slide onto a warm serving plate. Repeat with remaining oil, egg mixture and mushrooms.
4.
Top each omelette with bean sprouts, shredded onion and herbs, drizzle with dressing and scatter over peanuts. Serve with remaining dressing on the side.