In a small bowl or a mason jar, combine the olive oil, balsamic vinegar, honey, Dijon mustard, minced garlic, salt, and pepper. Whisk briskly or shake the jar with the lid on until the dressing is emulsified and smooth.

Take the steak out of the fridge about 20 minutes before cooking to let it come to room temperature. Preheat an outdoor grill or a cast-iron grill pan over medium-high heat. Pat the steak dry with paper towels, then season generously on both sides with kosher salt and black pepper.

Place the steak on the hot grill and close the lid. Cook for 3 to 4 minutes, then flip and continue grilling for another 3 to 4 minutes, until an instant-read thermometer inserted into the thickest part reads 130°F for medium-rare. Transfer the steak to a cutting board and let it rest for 5 minutes before slicing thinly against the grain.

Arrange the arugula on two serving plates or a large platter. Top with the sliced steak, cherry tomatoes, avocado slices, pickled red onions, crumbled blue cheese, and chives. Drizzle with the balsamic vinaigrette right before serving—you'll likely only need about half the dressing; save the rest for another salad later in the week.