I love the balance between the spicy curry paste and the creamy coconut milk; it’s one of my favorite flavor combinations because you get both salty and sweet.
Cut about ½-inch off the end of the lemongrass and discard then cut the stalks in half lengthwise. Set aside.
Place large sauté pan over medium heat, add the peanut oil and heat through. Add the garlic, ginger, lemongrass and the white part of the scallions. Cook, stirring frequently, for 1 to 2 minutes, until fragrant.
Add the bell pepper and continue cooking, stirring constantly, until the pepper has softened, about an additional 2 minutes.
Add the red curry paste to the pan, stirring constantly until aromatic, about 1 minute.
Stir in the coconut milk, fish sauce, palm sugar, lime zest, remaining lemongrass stalks and 1 cup of water to the pan. Stir to combine then season with salt and pepper. Reduce the heat to medium-low and simmer about 20 minutes. Do not boil the soup as the coconut milk may separate.
Season the shrimp on both sides with salt and pepper then add them to the mixture. Cook, stirring occasionally, 8 to 10 minutes, until the shrimp are opaque and cooked through. Add lime juice and half of the cilantro leaves. Discard the lemongrass stalks.
To serve: Divide the mixture among bowls and serve with jasmine rice. Garnish with the green parts of the scallions and the remaining cilantro.