3 tablespoons extra-virgin olive oil
6 tablespoons cold unsalted butter
1 onion, thinly sliced
1 tablespoon minced garlic
1 teaspoon dried oregano
1/4 cup tomato paste
1 cup of chicken stock
1 1/2 cups dry red wine
Remove the skillet from the heat. Strain the sauce into a small bowl, pressing on the solids to extract as much liquid as possible. Discard the solids in the strainer and return the sauce to the saucepan and bring back to a slow simmer. Cut the remaining 4 tablespoons of butter into small 1/2-inch chunks and whisk in the sauce a little at a time. Season the sauce, to taste, with salt and pepper.
Drizzle the sauce over the steak, or pour into individual serving ramekins. Enjoy with your favorite piece of steak.