Heat the oil in a large pot over medium until shimmering.
Add the ginger and curry paste (if using) and stir until fragrant (just 30 seconds so).
Add the leeks, greens, and mushrooms, and saute until the greens have wilted slightly.
Pour in the broth and soy sauce and raise heat to medium-high. Bring the soup to an active simmer and add the ramen noodles (if using dried, break apart the brick -- the noodles will cooperate more readily with a soup spoon if shorter).
When the noodles are tender (use package directions as a guide, although they might take a skosh longer to cook because the soup will not be boiling), reduce heat to low.
Place the miso in a small bowl, and add two to three tablespoons of the soup liquid. Stir until the miso dissolves into the liquid, then pour into the soup.
Add the kimchee, juice, and sesame oil, and stir well. Taste, and adjust for salt. If your kimchi is particularly strong or sharp, a light sprinkle of sugar over the soup will tame it right down.