Chop all vegetables, mince garlic and set aside.
Cut pork meat into bite size pieces. Marinate with mirin and black pepper, set aside.
Heat up a wok or a wide pan in medium high heat. Add 1 Tbsp oil and stir fry green onion for about 2 mins. Add minced garlic and dry shrimp and stir fry 1-2 mins. Lower heat and add black bean paste, sugar and oyster sauce. Stir fry for about 2 mins. Pour this sauce into a small bowl and reserve for later.
Using the same pan, pre heat on high. Next add 3 Tbsp oil, all the veggies, 1 tsp salt, pinch of pepper and stir fry for 2-3 mins.
Create a space in middle of the pan and add pork. Stir fry for about 4 mins. Combine the sauce and water into the pan, stir well. Close lid. Once it comes to a boil, lower the heat and simmer for about 4-5 mins or until the potatoes are soft. Stir occasionally.
Add corn starch slurry. Keep stirring and simmer for about 2 mins. Serve on top of rice. Garnish with toppings.