Start by draining your tofu. Wrap it in paper towels and place on a plate. Weigh it down with a heavy object for at least 30 minutes. Cut the tofu into cubes, and add to a large bowl together with the corn starch. Toss to coat evenly.
Make the Korean BBQ sauce. In a medium size bowl, whisk together ketchup, rice vinegar, soy sauce, agave, Sriracha, garlic and ginger. Add the sesame seeds and combine. Set aside whilst frying the tofu.
In a large wok or frying pan, heat some coconut oil or ghee on medium high.
Add the tofu to the pan. Cook each side of the tofu cubes until golden brown and crispy. This will take a few minutes on each side.
Remove all of the tofu from the pan, place in a bowl.
Clean the pan with paper towel and add half of the Korean BBQ sauce
Heat on low until the sauce starts to thciken (about one minute) , then add all the tofu back.
Toss to coat the tofu and cook for a minute.
Remove from heat and drizzle with remaining sauce.
Remove from heat and drizzle with remaining sauce.