Stir to coat the orzo in butter, and continue toasting the orzo over medium heat, stirring continuously, for 5 minutes. After 5 minutes, or once some of the orzo has started to brown, pour in the chicken broth (and optionally, white wine). Bring the liquid to a boil, then reduce the heat back to medium and simmer, stirring occasionally, for 10-12 minutes, or until all the liquid has been absorbed.