Step 1. Cook the egg
Place the whole, un-cracked eggs in a medium pot and fill with water to cover eggs by 1 inch (2.5 cm). Turn the heat to high and when boiling, turn the heat off and let the eggs sit in the hot water for 10 minutes. Promptly use a slotted spoon (keep the hot water in the pot) to remove the eggs and peel the egg under cold running water. Slice each egg in half.
Step 2. Cook the vegetables
If using fresh spinach: add the spinach to the hot water in the pot. Let sit for 1 minute. Use slotted spoon (keep hot water in the pot!) to remove spinach. Rinse spinach with cool water. Use hands to squeeze spinach leaves to remove as much water as possible. If using frozen spinach, defrost spinach, then squeeze leaves with hands to remove as much water as possible.
To briefly cook the bean sprouts and mushrooms, add the bean sprouts to the same hot water in pot. Let sit for 1 minute. Use slotted spoon to remove. Again, keep the hot water in the pot!
Step 3. Cook the ramen noodles per package instructions (I like Hime brand off of Amazon).
Step 4. Make the miso soup
In a large pot, add the stock, instant dashi and soy sauce. Bring to a boil over high heat. Remove from the heat and stir in the miso. Taste the soup and add an additional 1 to 2 tablespoons of miso if you’d like. Ladle soup into each bowl. Top each bowl with green onions.