Start by pressing your tofu. I will link to my tofu guide below if you would like a step by step of that process. Press the block of tofu for at least 30 minutes, the longer the better. You can even do it in the morning before you plan to make it.
When you are ready to eat, make the Korean BBQ sauce first. In a medium sized mixing bowl, whisk together the tomato sauce, rice wine vinegar, soy sauce, agave, Gochujang, the finely grated apple, garlic and ginger, and the sesame seeds. Whisk until combined. Set aside.
Then, take your pressed block of tofu, cut into cubes, or thinner rectangular slices like I did. Whatever you prefer. Add the tofu to a large mixing bowl, then sprinkle with the corn starch and salt. Toss to coat all of the tofu.
Now, heat a little bit of oil at the bottom of a non stick pan on medium high. Add the tofu to the pan, don't over crowd it, if the pan is too small to fit all of it, do it in two batches.
Brown the tofu on all sides, reducing heat as needed. It will take a few minutes on each side to get the tofu nice and crispy. Remove all of the tofu from the pan, place in a bowl.
If there is any leftover oil in the pan, wipe it out. Then return the pan to the heat and add about half of the Korean BBQ sauce. Heat on low for a minute, then add all of the tofu back to the pan.
Toss to coat the tofu, and cook for a minute. Then remove from heat. Serve immediately with rice and veggies if you want. Drizzle the remaining sauce over the top and garnish with scallions or chives!