Heat a wok or large straight-side skillet over medium-high heat. Add the coconut oil and heat for a minute.
Add the ginger, scallion whites, garlic, and lemongrass. Sauté until tender (1-2 minutes).
Add the green curry paste, sauté for 30 seconds.
Add the red bell pepper and sauté for a minute.
Add the yam. Brown slightly.
Add the cauliflower florets. Heat through.
Add the coconut milk, stock, kefir leaves and chile. Bring to a boil, then reduce to a simmer.
Simmer for 15-20 minutes until the liquid reduces by 25%.
Season to taste with fish sauce (the key to authentic flavor), soy, coconut sugar, and lime zest while maintaining a simmer.
Add the prawns or shrimp and continue to simmer until the shrimp is cooked through (approximately 3-5 minutes).
Add the lime juice and remove the kefir lime leaves. At the same time, warm the cooked rice (if necessary).
To serve: place 1/2 cup rice in a bowl. Top with 6 prawns, 1/4 of the vegetables and broth as desired (careful for the chile, if used). Garnish with scallion greens, cilantro, chopped peanuts, and a lime wedge.