Heat 1 tablespoon of butter over medium heat in your sauté pan. Once melted, add the chopped onions, minced garlic, and grated ginger. Cook, stirring frequently, until the onions are soft and translucent, about 3-4 minutes.
Sprinkle in the curry powder, salt, and black pepper. Toast the spices for about 1 minute, stirring constantly to prevent burning.
Sprinkle the flour over the onion and spice mixture, stirring to coat everything evenly. Cook for another minute. Slowly pour in the coconut milk, whisking as you go to prevent lumps. Add the coconut palm sugar and bring to a gentle simmer. Let it thicken for 3-5 minutes.
Add the shrimp to the pot in a single layer. Cook for 2-3 minutes on one side, then flip and cook 2 minutes more, or until they turn pink and opaque.
Remove the pot from heat. Stir in the remaining tablespoon of butter. Add fresh lime juice and chopped cilantro, folding gently to combine. Taste and adjust seasoning if needed.
Serve your One-Pot Coconut Curry Shrimp over steamed rice, quinoa, or alongside crusty bread to soak up the sauce.