Upgraded Cube Steak | Cooking Professionally

Ingredients

• 1/3 cup flour
• 1/2 teaspoon kosher salt
• 1/4 teaspoon pepper
• 2 pounds cube steaks
• 1 tablespoon olive oil
• 2 tablespoons butter
• 2 large onions, sliced into 1/4-inch-thick rings
• 1/2 cup red wine
• 4 cups beef broth, divided
• 2 tablespoons balsamic vinegar
• 1 teaspoon Dijon mustard
• 1 teaspoon rosemary, chopped, plus more, to taste, for garnish
• 1 tablespoon cornstarch
• water, to taste