Marinate tuna in Pineapple Teriyaki Marinade at least 2 hours or overnight if possible.
Preheat indoor grill (like The Griddler) to high heat or a skillet to medium high heat. Grill tuna for 2 minutes per side per half-inch thickness for a rare steak, or 3 minutes per side per half-inch thickness for medium. Tuna may require an extra minute or so per side if cooking in a skillet instead of on a grill. Let rest for 5 minutes before slicing.
If using steak
Take steak out of refrigerator and let it come to room temperature, covered. Preheat indoor grill (like The Griddler) to high heat or a skillet to medium high heat. Sprinkle both sides of steak with salt and pepper, then drizzle with olive oil and rub into the steak. Grill for 4-5 minutes per side for a medium rare steak. Let rest for 5 minutes before slicing.
For the salad
Combine all dressing ingredients and mix well.
In a large salad bowl, combine greens, carrots, and bell peppers. Toss with 2/3 of the dressing and divide between two plates. Top with sliced tuna or steak and drizzle with the remaining dressing. Top with sesame seeds, if desired.