To make the marinade, grab a large enough container that can accommodate your flank steak and place ¼ cup of olive oil, ⅓ cup of soy sauce, ¼ cup of apple cider vinegar, 2 tablespoons of lemon juice, 2 tablespoons of Worcestershire sauce, 1 tablespoon of Dijon mustard, 1 tablespoon of honey, 3 cloves of minced garlic, 1 teaspoon of sweet paprika, ½ teaspoon of ground cumin, ½ teaspoon of kosher salt, ¼ teaspoon black pepper in it. Whisk until smooth.
Cover and let it marinate in the fridge for at least an hour or overnight (no more than 24 hours.)
While the meat is marinating, make the salad dressing. In a small bowl, place 3 tablespoons of balsamic vinegar, 2 tablespoons of freshly squeezed lemon juice, 1 clove garlic, peeled and minced, 1 teaspoon kosher salt and 1/2 teaspoon freshly ground black pepper. Give it a whisk. While still whisking, slowly add the 1/4 cup of extra-virgin olive oil. Whisk until fully incorporated and smooth. Set it aside.
To grill the steak, preheat a gas grill to 500 degrees °F. Scrape the grill grates and coat them generously with the oil.
Place the flank steak on the grill and cook for 3-4 minutes on each side for rare (internal temperature is 130 to 135 °F), 4-5 minutes on each side for medium (internal temperature is 136 to 145 °F), or 5-6 minutes on each side for medium-well (internal temperature is 146 to 155 °F).
When it reaches your desired doneness, transfer the grilled flank steak to a platter and cover it with foil. Let it rest while you prepare the salad.
To make the salad, place 6 cups of roughly chopped romaine lettuce, 2 cups of corn, 1 cup of chopped cherry tomatoes, 3 small sliced radishes, 3 thinly sliced green onions, 1 sliced avocado, and a cup of mozzarella pearls in a large salad bowl.
Drizzle the dressing over the salad and toss to ensure that all of the ingredients are evenly coated. Add more seasoning to taste and adjust as needed.
Slice the steak against the grain (1/2-inch thick slices) and layer it over the salad just before serving.