Steak and Havarti Panini With My "secret Sauce"

"I was making myself a steak panini with the leftovers of my steak that I had had for dinner the night before, added havarti cheese, and wanted a nice sauce to go on it. So I just looked in the fridge and came up with this crazy concoction! It was SO GOOD, I decided to not keep it a secret! What's the fun of it if you don't share? Hope you enjoy it as much as I did!"
photo by a user photo by a user
Ready In:
1 panini


  • 2 2 slices whole wheat bread or 2 slices rye bread, or your own preference
  • 4 -8 slices cooked steak, depending on thickness of slices and size of bread
  • 2 slices havarti cheese
  • 2 slices onions
  • 3 fresh mushrooms, quartered or sliced
  • 2 tablespoons olive oil
  • Secret Sauce

  • 1 tablespoon A.1. Original Sauce
  • 1 teaspoon A.1. Original Sauce
  • 2 tablespoons mayonnaise
  • 14 - 12 teaspoon prepared grated horseradish, as hot as you like it


  • In small bowl add steak sauce. (Both amounts). Whisk in mayo til smooth and no longer lumpy, then whisk in horseradish. Taste, adjust to your own preferance, set aside.
  • In small saute pan, saute mushrooms and onion in ONE of the Tbls. of olive oil til crisp-tender or soft. Your own personal preferance. Set aside.
  • Get (lightly oiled) cast iron griddle (or panini maker) heating til medium-hot.
  • Lay out 2 pieces of bread.
  • Drizzle 1 Tbl. sauce onto each slice, then spread with back of spoon til evenly coated.
  • Pour rest of sauce into tiny bowl for dipping later.
  • Top one slice with 1 slice of cheese.
  • Top cheese with steak, piling on. As much or little as you like.
  • Top with sauted mushrooms and onions.
  • Top onions and mushrooms with second slice of cheese.
  • Place other slice of bread on top, sauce-side down.
  • Brush top of bread lightly with olive oil.
  • Place olive oil-side down onto heated griddle.
  • Brush new top with a little olive oil.
  • Press lightly, once, with spatula.
  • Brown bottom. Depending on how hot your pan is, this will take about 30 seconds to 1 minute. Check now and then to prevent burning. You will want this lightly toasted with nice grill marks.
  • When bottom is to likeness, carefully turn over with a spatula and brown other side. (*I lift a corner with my spatula, then carefully hold it up with my fingers, then get under it with my spatula so you don't wreck the bread.) Do the same way when the second side is done.
  • When done, carefully remove and place on a cutting surface and cut in half diagonally.
  • Serve hot with extra sauce for dipping. (Sauce can be used to dip your sandwich in, or great for dipping french fries, too!).
  • *Whatever steak you have on hand works just fine. Whether it be cooked at the moment, or leftover. I used leftover prime rib, but any good steak or tenderloin can be used.

Questions & Replies

Got a question? Share it with the community!


  1. This panini is totally awesome! I am proud to be the first to review it since we loved it so much! The cheese and fabulous sauce really make this a stellar sandwich along with the other ingredients. Kelly, you are a genius with this one! Mike


Hello! Former caterer and restaurant owner taking life slower now and just enjoying photographing my food creations and blogging them! Pop on over to my blog to see over 800 of my recipes at Wildflour's Cottage Kitchen @ !
View Full Profile

Find More Recipes