In a heavy sauce pan over high heat, combine wine, chicken broth and beef broth. Bring to a boil, and cook until mixture is reduced to 2 cups, about an hour. (This can be prepared a day ahead - cover and refrigerate).
In a small bowl, mix butter and flour. Heat 1 tablespoon olive oil in a large skillet over medium heat. Sprinkle steaks with salt and pepper, and saute until medium-rare, about 4 minutes per side. Transfer steaks to a plate.
Stir shallots, garlic and thyme into skillet. Add 2 cups reduced wine mixture to skillet. Bring mixture to a boil, scraping up any browned bits. Whisk in butter mixture until smooth. Boil sauce until thick enough to coat a spoon, about 2 to 3 minutes.
