Spicy Beef and Onion Sandwiches

I am seriously sad that I don't have a photo of these sandwiches. I have the hardest time using a recipe out of a cookbook that doesn't show what the finished product looks like, and here I am doing the same.

But these are YUMMY. In fact, Brian asked me this morning if there were any leftovers. NOPE. There are none. And his reply? "That's too bad".

The kids weren't mega fans, so this is more of an adult dish... but they did manage to pick out the onions and mushrooms, eat just the beef and then the roll it was on. Brian and I on the other hand had two of these each.

Spicy Beef and Onion Sandwiches (plenty to feed my family of 6)

1 to 1.5 lbs sliced sirloin steak, about 1 inch thick
1 large onion
2 TBSP Mustard Seed
1/2 cup Water
1 cup Sliced Mushrooms (I use baby portabello's)
2 Tbsp Sugar
2 Tbsp Cider Vinegar
2 tsp Olive Oil
Kaiser Rolls (we ended up using sourdough rolls and they were excellent!)
Dijon Mustard

Spray nonstick pan with cooking spray and cook beef just until done. Remove from pan and set aside.

Add Onion, mustard seed water and mushrooms to the pan. Cook until the water evaporates.

Add sugar, cider vinegar and olive oil to the onion mixture. Cook stirring frequently until brown. Add the beef back in and stir until combined.

Slice rolls, spread Dijon mustard on one half of the roll and top with beef/onion mixture.

I will take a picture the next time we make this and update. Because I WILL be making this again.