Sweet onions and red peppers top this hearty steak sandwich with melted Extra Sharp Cheddar.
Preheat grill pan on medium/high heat.
Season both side of steak with salt and pepper. Drizzle with olive oil.
Cook steak 4-5 minutes on 1st side, flip and cook 3-4 minutes more.
Transfer to a cutting board, let rest 5 minutes, then thinly slice against the grain.
Spread each slice of bread with Dijon mustard, layer with sliced steak, Old Croc Cheddar Cheese, sautéed spinach and roasted red peppers.
Place each sandwich back onto oiled grill pan, press down with spatula, grill until bread is browned and crisp.