In a pot, put the face mask and ear and pour water just enough to cover the pork, more or less 7 cups. Season with salt and pepper and bring to a boil. Simmer until fork tender, about 30 to 40 minutes.
Slice the pork mask and ears and grill it in a stove top grill or a non-stick pan until the fat is rendered and becomes brown crispy. Slice into strips and put into a bowl. Set aside.
In a separate bowl, mix the onion, bird's eye chili peppers, green pepper, onion, ginger, mayonnaise, calamansi juice, vinegar, sugar, salt and pepper. Mix thoroughly and set aside.
Heat and empty non-stick pan and saute the pork brain. Season with salt and pepper and stir until cooked and becomes a paste like consistency. Remove from the pan and put it on the bowl on top of the sliced pork mask.
Pour the mixture of vinegar and spices on the sliced pork mask and toss until the mixture is evenly distributed with the pork.
Season again with salt and pepper to adjust the taste. Garnish with spring onions.