Make the flank steak marinade by mixing together the 1/2 cup orange juice, 1/2 cup low-sodium soy sauce, 1/4 cup rice vinegar and 5 minced garlic cloves. Pour over the steak and marinate for at least two hours, preferably closer to 8.
To make the quick-pickled red onions, mix together the 1 cup water, 1 tbsp sugar, 1 1/2 tsp salt, 1/2 cup vinegar. Pour over the thinly sliced red onions and allow to pickle in a container for at least an hour.
Make the Creamy Balsamic Vinaigrette by adding 2 tbsp mayo, 2 tbsp balsamic glaze, 1/4 cup olive oil and a pinch of salt and pepper in a jar. Mix well and taste for adjustments.
To cook the flank steak, heat a large cast-iron over medium heat for 5 mins. Add a couple tbsp of avocado oil and sear the flank steak until it reaches an internal temp of 130 for medium rare (about 7 minutes per side, but use a meat thermometer).
Remove the steak and allow to rest for 5-10 minutes. Slice against the grain.
Assemble the salad with the greens, sliced baby tomatoes, avocado, crumbled goat cheese, quick-pickled red onion, sliced flank steak & creamy balsamic vinaigrette!