Grilled Flat Iron Steak and Pepper Sammy (Gluten Free)

I was looking to cook up some beautiful flat iron steaks but I only had about 30 minutes before work so I decided to make a quick lunch sandwich.  The result was a meaty, cheesey, hearty gluten free meal.  Don't feel like you have to use Flat Iron's; this is a great way to use any kind of steak.  Even better, slice up some leftovers from the night before and make this sandwich for lunch the next day.  Fantastic.

Wanna take a bite???

Ingredients (for 2 sandwiches):
4 slices Gluten Free Italian Baked Bread
2-4oz flat iron steaks, set out to room temp
1 bell pepper sliced or 1/2c frozen bell pepper slices
2 slices provolone cheese
1tbs mayonaise
1tbs dijon mustard
2tbs butter

Directions:
1. Preheat grill to high.  When hot, turn to medium high.  Salt and pepper the steaks generously and grill on both sides until desired doneness.  Set out for a few minutes before slicing.
2. Meanwhile, if using fresh peppers, cut into 4 pieces and place on grill with steak.  When soft and charred on both sides, take off the grill and slice.  If using frozen peppers, heat a tsp oil in a skillet and saute until done.  Make sure you drain all the liquid (you don't want them to sog out your bread!)
3. Spread 1/2tbs mayo and mustard on one side of a slice of bread.  Top with steak, peppers and cheese.  Then top with the other slice of bread.
4. In a nonstick skillet, heat butter over medium high heat.  Add sandwiches and turn heat to medium.  Cook on both sides until bread is grilled and cheese is melted.  Serve hot.