In a large bowl, combine the milk, condensed milk, evaporated milk, table salt, and vanilla extract.
Next, add the cornstarch to the mixture and mix everything well together.
Now heat up a pan on medium-low heat.
Add unsalted butter to the pan and evenly coat the pan with the melted butter.
Now, using a sieve, pour the mixture into the pan through the sieve.
Using medium heat, stir the mixture around until it starts to thicken up.
Reduce the heat to medium-low once the mixture starts to thicken up, and continue cooking the mixture until it turns into a thick paste.
Now grease a container with some cooking oil. This will make it easier to remove the milk mixture after it has cooled down.
Next, pour out the mixture into the greased container.
Use a spatula to smooth out the top of the mixture, then pick up the container and slap it down a few times to spread out the milk mixture evenly in the container. Make sure to do this quickly while the mixture is still hot, otherwise, it will start to set.
Allow the mixture to cool down, then cover it with a lid and place it in the fridge, and let it cool down for at least 3 hours.
Once the milk mixture has solidified, remove it from the container onto a cutting board.
Cut the milk mixture into equal-sized pieces. You can cut it into whatever size you prefer, but I like to have mine in long strips resembling fish sticks.
Add some oil to a pan or pot and heat it on medium-low heat until it reaches around 175°C (350°F).
Now it’s time to prepare the breading.
Beat and whisk 1 1/2 eggs into a bowl and set them aside. In another bowl, add in your cornstarch and set it aside. Finally, in a large bowl or plate, add your panko bread crumbs.
Now dip each piece of the milk mixture into the cornstarch first, followed by the egg mixture, and finally into the panko bread crumbs. Try to evenly coat all sides of the milk mixture with all 3 ingredients.
Now add the pieces into the hot oil. The temperature will drop as soon as you add in pieces, so I don’t recommend adding more than 3-4 pieces at a time. Also, don’t immediately touch the fried milk pieces soon after adding them into the oil, as the crust hasn’t hardened yet.
Fry the pieces with the hot oil at a temperature of around 145°C-155°C (293°F-311°F). Do not go past this as it will get browned very quickly. Also, do not fry using a lower temperature as it will soak up a lot of oil.
Fry the milk mixture until it’s golden brown on both sides (approximately 3-4 minutes total).
Repeat this for the rest of the pieces.
Once done, rest the fried milk pieces on a wire rack to drain out some of the excess oil, then serve while still hot.