Korean soy sauce, (called Joseon ganjang (조선간장) in Korean) is a byproduct of the production of doenjang (Korean fermented soybean paste). Joseon ganjang, thin and dark brown in color, is made entirely of soy and brine, and has a saltiness that varies according to the producer. Traditionally in Korea, we have different kinds of soy sauce, depending on the length of the fermentation time. Basically we use 2 types of soy sauce the most. One is normal soy sauce, which is fermented for more than 3 years. The other is soup soy sauce which is fermented for 1 or 2 years. The longer you keep the soy sauce the darker color, and the stronger flavor. Nowadays, many Korean people just buy soy sauce from the store instead of making it at home since it is difficult and time consuming.
MiYeok JulGi is usually used for a Korean side-dish, MiYeok JulGi BokkEum in Korea. You can buy salted seaweed stems from a Korean or Asian store. Look for them in the refrigerator section. Since they are heavily salted, you will have to soak them in water at least one night before cooking. This is chewy and salty enough to eat without adding extra salt. If you want to a cook small amount and save some for later, cut them (Of course, they should be already soaked in water) into the size you want, and keep them in the freezer.
Hot pepper oil (gochu gireum=고추기름) is a condiment made from vegetable oil that has been infused with dried chili peppers and sometimes also additional ingredients. It is also employed in the Korean Chinese noodle soup dish jjamppong. Chili oil is typically red in color. It is made from vegetable oil, often soybean oil or sesame oil, although olive oil or other oils may be used. Other spices may be included such as Sichuan pepper, garlic, or paprika. The spices are soaked in oil. Commercial preparations may include other kinds of oil, water, dried garlic, soy sauce, and sugar. Recipes targeted to Western cooks also suggest other popular oils such as canola, peanut, grapeseed, olive, and any dried or fresh chili peppers. Chili oil is commercially available in glass jars, although it may also be made from scratch at home.
Frying mix is one type of flour Korean people use for fried foods. As the name says, it’s already mixed with various ingredients for making frying batter. Simply mix this powder with some water. I usually use a mix of half frying mix and half normal flour for my frying since it tastes better that way.