Pour crêpe mix along with coconut milk, water and spring onion into a bowl and stir well. Keep in the fridge until ready to use. Mix all crêpe filling ingredients in a bowl (except stir-fried mushrooms) and keep in the fridge for at least 30 minutes. Prepare salad and dressing.
Place a non-stick skillet on high heat and drizzle with oil. Toss in a little bit of the filling mix (except mushrooms) and cook until half-way done. Ladle in the batter and swirl pan to make a thin layer. Cover with lid and lower heat to medium and let cook for a few minutes. When the edges of the crêpe start to pull away from the pan and the bottom turns a golden brown, fill crêpe with the stir-fried mushrooms and fold over to make a half circle. Let it finish cooking for another minute or so and transfer to plate. Serve immediately with salad and dressing.