1. Add the olive oil into the pan and saute the garlic and onion until they turn brown.
2. Add the mushroom, A1 sauce, tomato paste, red wine, broth, and flour. Stir the mixture well for about 2 minutes. Then the sauce is done.
3. Prepare a cast iron grill pan. Add the oil on the surface and heat the pan with medium heat until it is very hot. Put the steak on the grill pan and saute each side for about 3~4 minutes. (The cooking time may vary because of the different size and thickness of the steak) This should bring the steak to medium. (You can use the panini press to make the steak wonderful with the burn mark.).