2 tablespoons olive oil
1 tablespoon butter
4 garlic cloves, thickly sliced
1/2 onion, chopped
1 teaspoon red pepper flakes
1 tablespoon chopped fresh rosemary, ground into a fine powder
or 1 teaspoon dry rosemary
2 cups balsamic vinegar
2 cups chicken broth
1 tablespoons of softened butter mixed with 1 tablespoon of flour into a soft paste (optional)
Balsamic Vinegar Sauce
Bistecche all’Americana conl il Sugo Balsamico
In a saucepan, cook the butter and garlic over medium heat for 2 to 3 minutes. Add the onion, rosemary and the red pepper flakes and cook for 4 more minutes. Add the balsamic vinegar, raise the heat to high, and cook stirring well until it reduces by half, about 5 minutes. Add the broth, bring to a boil then simmer for 35 to 40 minutes. If you like the sauce thicker bring it back to a boil and add the butter-flour paste 1 teaspoon at the time whisking well, until it reaches the consistency you like. You do not need to use all of the paste.
If you like a fancier look strain the sauce through a fine mesh and before you serve it place back in the sauce pan and over low heat, add 1 tablespoon of plain softened butter, stirring well until it is all melted. This will add some sheen to the sauce.