Flat Iron Steak and Spinach Salad

Preheat an outdoor grill for medium-high heat; lightly oil the grate.

Season flat iron steak on both sides with salt and pepper. Cook to the desired degree of doneness on the preheated grill, about 5 minutes per side for medium-rare. Let steak rest in a warm area.

Heat olive oil in a large skillet over medium-high heat. Stir in onion and cook until it begins to soften, about 4 minutes. Pour in Italian salad dressing; bring to a boil, then stir in red peppers and mushrooms. Reduce heat to medium and cook until peppers are tender, about 5 minutes. Remove vegetables from the skillet with a slotted spoon; set aside.

Increase heat to medium-high and add red wine to the skillet. Simmer salad dressing and wine until reduced to a syrupy sauce, about 5 minutes.

Meanwhile, divide spinach leaves onto serving plates. Thinly slice steak across the grain. Spoon warm, cooked vegetable mixture over spinach leaves, then place sliced steak on top. Spoon on reduced red wine sauce and sprinkle with blue cheese.