Steak Salad

Bahan-bahan (4 porsi)

• 1 1/4 pounds flank steak (skirt steak, or hanger steak)
• 1 1/2 teaspoons kosher salt
• 1/2 teaspoon ground black pepper
• 2 tablespoons balsamic vinegar
• 1 tablespoon extra-virgin olive oil
• 1 large red onion
• 1 pint cherry tomatoes
• 3 cups mixed greens (chopped romaine, spinach, or lettuces of choice)
• 3 cups arugula
• 4 ounces crumbled blue cheese (such as gorgonzola, divided)
• extra virgin olive oil (for grilling the onion)
• 1/4 cup balsamic vinegar
• 3 tablespoons extra virgin olive oil
• 1 teaspoon Dijon mustard
• 1 teaspoon honey
• 3/4 teaspoon kosher salt (plus additional to taste)
• 1/8 teaspoon ground black pepper (plus additional to taste)