In the slow cooker insert, combine the onion, chicken, wine, lemon juice, olive oil, parsley, salt, pepper and thyme.
Cook on low for 5 to 6 hours, or until the chicken is tender and falling apart.
Turn the cooker to high and add the orzo. Stir and cook on high until the orzo has absorbed most of the liquid already in the slow cooker. Start adding hot water, 1/2 cup (120 ml) to begin with and then 1/4 cup (60 ml) at a time, as needed for the pasta to cook through. Total cooking time for the pasta should be 25 to 35 minutes. Turn the slow cooker off when the orzo is al dente and the consistency is quite wet and “sloppy” looking, since the pasta will continue to absorb liquid as it rests.