Yield: 4 Servings
| Measure | Ingredient |
|---|---|
| 1 cup | Balsamic vinegar |
| 4 \N | Cl Garlic; sliced |
| 4 pinches | (2-inch) fresh rosemary |
| 2 tablespoons | Butter; optional |
Put all the ingredients except the butter into a saucepan and bring to a boil. Reduce the heat and simmer until it is reduced by half, about 10 minutes. The sauce is ready when it coats the back of a spoon. Add the optional butter and stir well.