For the crispy tofu

• 1 14 oz block of tofu (about 396g- don't worry if your tofu is bigger/ smaller- just adjust the quantity of the other ingredients accordingly.) Cut into 1-inch cubes. I like to use Chinese tofu as it is firm enough to pan-fry but still very soft when you bite through the crisp exterior. Do NOT use silken tofu as it'll be VERY difficult, almost impossible, to fry! In a pinch, you can use firm tofu, but you won't get the same delightfully oozy interior that you will with Chinese tofu.
• 1-2 Tablespoons cornflour Substitute: potato starch
• ½ Tablespoon sesame seeds lightly toasted: white or black work though I find white sesame seeds make the dish more appealing.
• ½ sprig green onions Optional
• a drizzle of sesame oil Optional

For the sauce

• 5 Tablespoons  Low-sodium light soy sauce if you're on a gluten-free diet, you can use coconut aminos or 1 of these light soya sauce alternatives. Do not use dark soy or sweet soy instead.
• 2½ Tablespoons sake Substitute: soju or mirin
• 2½ Tablespoons mirin Substitute: soju or sake + sugar
• 1¼ Tablespoons white sugar I don't recommend brown sugar or maple syrup as I prefer the cleaner taste of white, but if you have no choice, it won't ruin the recipe.
• 3 cloves garlic: peeled and minced, optional
• ½-1 Tablespoon white rice vinegar or to taste, optional, substitute: juice from 1 calamansi lime