Heat the skillet again over medium heat and add butter. When foaming stops add the onion and cook until just browned. Add the garlic and cook until fragrant. Add the toasted orzo and remove from heat. Add 3 1/2 cups of stock and the wine and stir together. Return to the heat and bring to a boil. Reduce the heat to low and simmer, while stirring, until all liquid is absorbed and orzo is al dente. Orzo may be held at this point, covered and off the heat.