Cut the pork belly into 1-inch cubes. Mince the shallots and garlic and add together with the pork into a large bowl.

In the same bowl, add together the oil, salt, and black pepper. Stir or toss with your hands until everything is evenly coated. Cover and put this bowl aside to marinate while you do the next step.

In a large saucepan over high heat, mix together the sugar and 2 tbsp. of water. Bring to a boil and carefully monitor until it starts to brown. The caramel will burn really quickly, so make sure you are watching it and stirring at all times.

Once the caramel has reached a golden brown color, immediately add the contents of the pork bowl and turn the heat down to medium. Constantly stir to coat the pork with caramel for about 5 minutes.

Add 1 ½ cups of water, the fish sauce, and the soy sauce, then bring the heat down to allow a simmer. The pork will need to be left at this heat for 45-60 minutes. Stir occasionally and spoon off any fat lard that floats to the top. The excess fat can be thrown away. Once the pork has reached your preferred level of tenderness, take it off the oven and set aside.

Use a vegetable grater to cut the cucumber into thin slices. Carefully cut the chili pepper in half, remove the seeds, and slice thinly. Destem the cilantro and roughly chop.

To assemble the sandwich, cut each bread roll in half. On one half, spread the Kewpie mayo. On the other half, spread a generous helping of pate. Spoon the pork on top of one half and drizzle with sauce. Pile on cucumber, chili slices, pickles carrots, and top with a sprinkle of cilantro. Place the other half on top and voila!

Enjoy your delicious pork belly banh mi!