Heat the oil in a saucepan over high heat. Add the onions, garlic, orzo, salt, and pepper and stir-fry for 2 minutes. Stir in the mint and stock and bring to a boil.
Reduce the heat to medium and cook, stirring occasionally, for 20 minutes. Remove from the heat and fold in the butter until thoroughly incorporated. Serve immediately.
Yield: about 3 cups