Before starting, preheat your broiler to high.Wash and dry all produce. Core, then cut pepper into 1/2-inch strips. Halve rolls. Pat steak dry with paper towels. Sprinkle half the Italian Seasoning (use all for 4 ppl) all over steak, then season with salt and pepper. Set aside.

Heat a large non-stick pan over medium-high heat. When hot, add 1 tbsp oil (dbl for 4 ppl), then onions and peppers. Cook, stirring occasionally, until tender-crisp, 3-4 min. Season with salt and pepper. Transfer to a plate.

Add 1/2 tbsp oil (dbl for 4 ppl), then steak to the same pan. Sear until golden-brown, 1-2 min per side. (NOTE: It's okay if it doesn't cook all the way through at this step!) Remove pan from heat and transfer steak to a foil-lined baking sheet. Broil in the middle of the oven, until cooked to desired doneness, 4-7 min.\*\*

While steak finishes cooking, whisk together half the balsamic glaze and 1 tbsp oil (dbl for 4 ppl) in a large bowl. Set aside.

Thinly slice steak. Remove foil from the same baking sheet, then arrange rolls, cut-side up. Divide mayo between rolls. Top bottom roll with steak, then drizzle over remaining balsamic glaze. Add half the veggie mixture over top. Sprinkle cheese over veggies. Broil, in the middle of the oven, until cheese melts, 2-3 min. (TIP: Keep an eye on them so that they don't burn!)

Add spinach and remaining veggies to the large bowl with dressing. Season with salt and pepper, then toss to combine. Divide Italian sandwiches and spinach-pepper salad between plates.