Set a large soup pot over medium heat. Add the water, onions, celery, garlic, ginger and jicama. Simmer for 10-15 minutes until the onions are tender.
Stir in the salt, pepper, mustard, parsley and peas. Return to a boil and simmer another 5 minutes, or until the peas are tender.
Remove from heat. Mix in the wasabi paste and 2 tablespoons lime juice. Blend with an immersion blender or standard blender, being careful not to burn yourself with the hot soup. (If using a standard blender, open the vent, but cover the top with a kitchen towel so the hot soup doesn't splash out.)
Taste, then add additional lime juice, salt and pepper if needed. Ladle the soup into bowls and garnish with coconut milk and wasabi peas.
Notes
Fresh green peas may need a bit longer cooking time, since frozen green peas have already been blanched.