Combine pineapple juice, sugar, soy sauce, ginger, vinegar, and garlic in a saucepan.
Simmer over medium heat. Reduce by half until syrupy. It should coat a spoon.
Preheat your grill to high heat. Aim for about 450°F.
Pat steaks dry with paper towels. Season both sides with salt and pepper.
Place steaks on oiled grates. Sear 4-5 minutes per side.
Brush steaks with the pineapple reduction during the last 3 minutes.
Grill pineapple rings for 2 minutes per side. Look for grill marks.
Transfer steaks to a platter. Let them rest for 7 minutes.
Serve steaks topped with a pineapple ring. Add a drizzle of extra glaze.