1 1/2cupcooked corn kernelsfresh or frozen, at room temperature
1large jalapenoseeded and diced
1teaspoonfresh ginger rootpeeled and grated
Salt and pepperto taste
Place a large cast iron skillet over medium-high heat. (Or you can cook the scallions and steak on the grill.)
Trim flank steak of excess fat and tough connective tissue over the surface of the steak. Using a paring knife, insert the knife at an angle - almost all the way through the steak - to create multiple holes all over the surface of the steak. Flip the steak over and repeat the process on the other side. Be sure to make the second set of holes parallel the l to first set so you don't create big holes in your steak.
Rub each side of the steak with 1/4 teaspoon ground mustard, 1/2 teaspoon salt, and 1/4 teaspoon pepper.
Add 1 tablespoon olive oil to skillet. Place scallions in the skillet, and cook for 30 seconds to 1 minute per side until greens have wilted and slightly charred. Remove from skillet and set aside.
Melt butter in the skillet, and add flank steak. Sear the steak for 2 minutes on each side until a nice brown crust forms. After steak is seared, remove skillet from heat. Allow steak to finish cooking in skillet for 5 minutes. Remove steak from pan and allow to rest for 10 minutes, loosely cover with aluminum foil.
In a medium bowl, combine corn, jalapeno, lime zest, lime juice, ginger, and Sriracha until well combined. Season salsa with salt and pepper to taste.
Once steak has rested, slice steak into thin strips at an angle. Place steak slices on a large platter. Top with salsa and then wilted scallions. Serve family style.
If you want to add some heat to your salsa, up the amount or Sriracha you use.