Put 2 Tablespoons of vegetable oil in a large frying pan. Place the frying pan on a medium heat. Then put in the sliced spring onion pieces.
Once spring onion starts to sizzle, place in pork pieces. When most of the red is cooked away from the pork, add the onion and cabbage in.
Then add the fried black bean paste, along with the sugar. Stir-in the black paste and coat all of the vegetables.
Then add two cups of water into the mixture.
While the pot starts to re-boil, take out a small bowl and make starch water: Mix in 2 tablespoons of (potato) starch powder with 6 tablespoons of water.
Once the pot is boiling, put in this starch water into the sauce. Don't add all of it at once. Add a little and see how much more you need to thicken-up into the consistency of a curry sauce.
Let it gently simmer for 5-8 minutes on medium heat. Then turn off the heat. Scoop sauce over noodles and garnish with cucumber.