Heat oil in a large frying pan over medium heat. Sauté onion until softened, about 2 minutes. Add spices, garlic, and shrimp and cook, stirring, until fragrant, about 2 minutes. Add coconut milk and salt; simmer 10 minutes to meld flavors.
Spoon curry over rice on plates. Garnish with cilantro.
Note: Nutritional analysis is per serving.