Wash spinach carefully, removing old leaves. Separate the leaves from the bunch -- you can leave some of the red roots on, they're tasty.
Get a pot ready (4 qt), and fill pot 3/4 full with cold water. Bring to a rapid boil. Dip the spinach and mix for about 1-2 min. Rinse the boiled spinach once and drain. Squeeze out the excess water holding one handful of spinach at a time. Put spinach in a medium bowl.
Add soy sauce, garlic, sesame oil and green onions to the prepared spinach. Sprinkle a dash of salt to taste and garnish with sesame seed powder. For a variation, you can also add 1-2 tbsp of hot pepper powder (gochugaru 고추가루), and a dash of sugar to taste.