Wonderful tasting sandwich. Wasn't sure if I was going to like it but it was delicious. I fried the onions and mushrooms together in butter. I used 4 Steak-Ums for 1 sandwich and served on a hamburger bun. This one will be going into my Sandwich cookbook to make over and over.
Really good. Topped with provolone.
What a wonderful sandwich Lazyme. We enjoyed it very much. My picky dh was very impressed with this tasty treat. The sauce was very rich and flavorful, the onions and mushrooms a perfect accompaniment. I used a sirlion steak and portugese bread. Wonderful simply wonderful. I will be making this often. Thanks so much for sharing.