Heat the coconut oil in a large skillet or wok over medium heat until shimmering. Add the diced onion and cook, stirring occasionally, until translucent and fragrant, about 5 minutes.
Add the minced garlic and grated ginger to the skillet. Sauté for about 1 minute until fragrant, being careful not to burn the garlic.
Stir in the curry powder, turmeric, and cumin. Toast the spices for about 30 seconds, until they release their warm aroma and turn a bit darker.
Pour in the coconut milk, stirring well to combine. Bring the mixture to a gentle simmer, allowing it to thicken slightly and smell creamy and fragrant, about 3 minutes.
Add the peeled, deveined shrimp to the curry. Cook for 3-4 minutes, stirring gently, until the shrimp turn opaque and firm.
Squeeze the juice of half a lemon or lime into the curry. Stir and taste, adjusting salt if needed. Let it simmer for another 2 minutes to meld the flavors.
Remove the skillet from heat. Garnish with chopped cilantro and a squeeze of fresh citrus right before serving. Serve hot over steamed rice with extra herbs for a vibrant finish.