Professional cooks rely on top of the line water ovens. But, for your home, you could improvise by cleaning and storing lukewarm water in the kitchen sink, a thermometer and a stop-watch to keep track of the temperature and time respectively. Similarly, low temp rice cookers may also be used in conjunction with a timer.
Nevertheless, once perfected, you’ll be able to reproduce the same consistency and flavor any number of time just by regulating the temperature of the water bath and keeping an eye on the cooking time.