In order to remember to buy sausage, ham, onions, and parsley for his pasta sauce, enzo forms the word "shop" with the first letter of each item. enzo is using a memory aide known as

I believe the memory aide is known as Chunking

Chunking refers to the process of dividing our memory into several smaller pieces group them into larger unit.

Doing this will form a certain trigger that would arouse our memory to remember certain things after we hear or see the word associated with that memory.