To make the sweet potato fries, pour oil for deep-frying into a large saucepan and heat it over a medium heat until it is hot but not smoking. Season the sweet potato planks with salt and pepper and deep-fry them in batches until cooked and crisp, about 1 or 2 minutes. Remove from oil with a slotted spoon and drain on paper towels. Keep hot to serve with the shrimp when ready.
To make the shrimp, pour the 1/4 cup oil into a heavy-based saucepan or skillet over a medium heat. Toss in the shrimp, garlic, bell pepper, and chile and cook for about 3 or 4 minutes. Add the curry powder. Stir well and cook for a further minute, then add the coconut milk. Season with salt to taste, turn the heat up to high, and continue cooking, stirring constantly, until the sauce is much reduced and thick, about 10 minutes. Stir in the cilantro and remove from heat. Serve immediately with the sweet potato fries, generously garnished with cilantro leaves.