Slice green onion to 2" pieces and put them in a large mixing bowl. Sprinkle 1 table spoon of anchovy sauce and toss. Let it sit for 10 minutes.
Meanwhile, water and sweet rice flour in a small pot and place the pot over medium high heat. Cook the mixture until thickens, about, 2-3 minutes, as whisking continuously. Remove from the heat and set aside to cook.
In a blender, puree together apple, ginger, and the rest of fish sauce until smooth.
Combine the rice glue, apple ginger puree with Korean chili flakes in a bowl and add sugar; mix well to make the seasoning paste.
Add the seasoning paste to the green onion in a large bowl, add in the dried pollock, and black sesame seeds; toss to incorporate all.
Line an airtight glass container with a large plastic bag. Put the kimchi inside the plastic bag and tie to seal. Close the lid and let it sit in the room temperature for 2 days, then store in the fridge for another 3-4 days. Serve the kimchi with any korean meal.
* To make anchovy stock, simmer 5-6 large dried anchovies in 2 cups of water for 10 minutes. discard the anchovies and reserve the stock.
Keyword dried pollock, green onion, green onion kimchi, Korean scallion pancakes, pollock fish, scallion