Pre-heat grill to 450 degrees and spray with grilling spray so steaks do not stick.
Grill steaks 5 minutes per side, then remove and cover to keep warm while making the sauce.
For the Ginger Teriyaki Sauce
In a medium sauce pan over medium heat, add soy sauce, water, apple cider vinegar, sesame oil, minced garlic, grated ginger, brown sugar. Mix to combine and bring to a slight boil.
Mix corn starch and water and pour into teriyaki sauce, stir to combine and reduce heat until sauce thickens, about 1 minute. Pour over steaks and garnish with green onions and serve over rice (optional)