Salt and pepper your steak. Heat a cast-iron skillet or griddle over medium-high heat. Add butter and cook just until melted, then place the steak in the pan. Cook until nicely browned, about 5-6 minutes.
Whisk together the balsamic vinegar and white peach juice concentrate. Set aside 3 tablespoons of the mixture.
Flip the steak, drizzle with remaining vinegar mixture, then top liberally with bleu cheese. Cover your pan with a lid to allow the steak to cook to a perfect, warm pink center (about an additional 4-6 minutes depending on how thick your steak is).
Gently transfer the steak to a cutting board and allow it to sit for about 10 minutes before slicing. in the meantime, toss together the ingredients for the salad. Mix together the olive oil and remaining balsamic vinegar mixture. Toss into salad, salt and pepper to taste.
Serve salad with sliced sirloin. Enjoy the heck out of it.