Wash and dry all produce. Adjust rack to middle position and preheat oven to 450 degrees. Cut potatoes in half lengthwise. Toss on a baking sheet with 2 TBSP olive oil, 2 tsp Italian seasoning (we sent more), salt, and pepper. Roast in oven until browned and tender, about 20 minutes, tossing halfway through.

Cut tomatoes in half lengthwise. Cut mozzarella into cubes about the same size as the halved tomatoes. Toss together tomatoes, mozzarella, and 1 TBSP olive oil in a medium bowl. Season with salt and pepper. Set aside.

Pat steak dry with paper towels. Season generously all over with salt and pepper. Around the same time that the potatoes are halfway done roasting (about 10 minutes after they've gone in the oven), heat 1 TBSP oil and 1 TBSP butter in a large pan over high heat.

Add 2 steaks to pan once hot. Cook until browned on bottom, 2 to 3 minutes. Flip and continue cooking until browned on other side, about 2 minutes more. Transfer to a plate, cover loosely with aluminum foil, and set aside. Heat another 1 TBSP oil in same pan and cook remaining steaks as you did the first two.

Pick basil leaves from stems and tear into rough pieces; discard stems. Add leaves to bowl with tomato and mozzarella salad and toss to combine.

Divide steak between plates, then spoon tomato and mozzarella salad over top. Drizzle with balsamic glaze (to taste—you may not use all). Serve with potatoes on the side.