Soak the mushrooms - For the best flavour, soak the dried mushrooms in cold water, then cover and leave overnight at room temperature. If you don't have time, soak mushrooms in boiling water for 20 to 40 minutes. For both methods, add some weight, like a small plate or bowl, to hold the mushrooms down or they'll float to the top. The mushrooms should look soft and plump after soaking.
Chop the chicken into small bite-sized pieces and place them in a large bowl along with the marinade ingredients. Leave to marinate for 15 minutes at room temperature. Slice the sausages thinly and rinse the rice 3 to 4 times or until the water runs clear. Get rid of as much water as you can on the last rinse.
Heat oil in a large deep frying pan or wok over high heat, then add the sausages. Stir-fry them for 1 to 2 minutes or until they look translucent. Optional - remove the sausages from the pan. Place in the garlic and ginger and stir-fry quickly for 1 minute or until fragrant, then add the sausage, mushroom, and chicken, including all the marinade. Stir-fry until the chicken has cooked.
Reduce the heat to low, then pour in the water, then add rice, sesame oil, sugar, salt and pepper. Stir to combine. Remove from heat and carefully transfer the mixture into the rice cooker bowl. If your rice has a clay pot setting, select this function. If not, select jasmine rice or the white rice setting. Once cooked, allow the chicken rice to rest in the cooker for 10 minutes. Fluff up the rice, then stir in the spring onions before serving.