Heat approximately one tbsp. of grapeseed oil in a sauce pot until it shimmers and moves easily across the pan but before it starts to smoke.
Add curry paste and break it up with a wooden spoon, Cook the curry paste approximately 5 minutes then add the coconut milk.
Add the piece of ginger and the lemon grass, bring to a simmer. Add the cilantro and basil stems. Season to taste with sugar and fish sauce or, if fish sauce is unavailable, salt.
Allow the herbs to steep 10 - 20 minutes, then remove along with the ginger and lemongrass.
Add the peppers and cook until they are crisp-tender. Remove with a slotted spoon and reserve. Add snap peas and cook until crisp and tender. Remove with a slotted spoon.
Bring the coconut milk back to a gentle boil. Add the fish, remove from heat immediately and cover. Check the fish after five minutes. If they are not completely cooked, return the pot to the heat but do not let it boil. Continue in this manner until the fish is cooked.
Serve the fish and the vegetables over jasmine rice. Top with cilantro leaves, basil leaves and serve with lime wedge.