Press the tofu, ideally using a tofu press, or if you don't have a tofu press, by placing the tofu on a plate, with another plate on top of it, and then stacking something heavy on top of that, like a heavy pot or stack of books. Leave to press for 30 minutes.
When pressed, slice each block of tofu into 3 rectangular blocks, so that you have 6 rectangles.
Brush the tofu with sesame oil and sprinkle it with salt and pepper.
Mix up your basting sauce by adding the toasted sesame oil, rice vinegar, maple syrup, hoisin sauce, onion powder, garlic powder, ginger powder and cayenne pepper to a measuring jug. Whisk it into a sauce.
Lightly brush a grill skillet with sesame oil and heat it for around 6 minutes on medium to high heat until hot.
Place three of the tofu blocks onto the hot skillet. They will stick to the skillet.
Grill the tofu for 5 minutes. After 5 minutes they will have grill lines and should release from the skillet easily without sticking.
Flip the tofu over and grill for 5 minutes on the other side.
Remove the tofu from the skillet and repeat with the remaining 3 tofu rectangles.
Then return the tofu to the skillet, 3 pieces at a time and lightly brush the basting sauce on both sides.
Serve over basmati rice and pour over the rest of the sauce.
Top with chopped green onions and a sprinkle of white sesame seeds.