1. In a large, deep skillet, heat 2 tablespoons of the oil. Add the ginger, garlic, jalapeño and minced scallion and cook over moderate heat, stirring, until fragrant, 3 minutes. Add the bell pepper and sweet potato, season with salt and pepper and cook, stirring frequently, until barely softened, 3 minutes. Add the zucchini and curry paste and stir to coat the vegetables with the curry.
2. Add the coconut water and lime juice and simmer over moderate heat until the sweet potatoes are nearly tender and the liquid is reduced by half, about 20 minutes. Stir in the kale and cilantro and cook just until the kale is wilted. Add the sour cream and season with salt and pepper.
3. Light a grill or preheat a grill pan. Rub the pork with the remaining 1/2 tablespoon of oil and season with salt and pepper; grill over moderate heat, turning, until cooked through, 12 to 15 minutes. Let the pork rest for 5 minutes, then slice and arrange on plates with the vegetable curry alongside. Garnish with the sliced scallions and serve.