Remove the shells and dark vein from the shrimp. Rinse them briefly under cold water, then drain well.
Place the shrimp between layers of paper towel and press gently until the surfaces are dry. Removing excess water helps the shrimp sear instead of steam.
Place the shrimp in a bowl. Add ½ teaspoon salt, black pepper, and paprika. Toss until each shrimp is lightly coated.
Heat the oil in a large skillet over medium-high heat for about 1 minute.Arrange the shrimp in one layer. Cook for 60 to 90 seconds on the first side. Turn them and cook for another 30 to 60 seconds.The shrimp should be pink on the outside but not fully cooked in the center. Transfer the seared shrimp to a clean plate. Leave the oil and browned bits in the skillet.
Lower the heat to medium. Add the chopped onion and cook for 3 to 4 minutes, stirring often, until soft and slightly clear.Add 1 teaspoon oil if the skillet becomes dry. Add the minced garlic and cook for 30 to 45 seconds. Stir constantly and keep the garlic pale to prevent a bitter flavor.Add the red pepper flakes at this stage when making a spicy version. Shake the coconut milk can before opening it. Pour the coconut milk into the skillet.Scrape the bottom of the pan with a wooden spoon or spatula to release the browned bits. Stir until the sauce looks smooth. Bring the sauce to a gentle simmer. Lower the heat to medium-low and cook uncovered for 5 to 7 minutes.Stir two or three times. The sauce is ready when it lightly coats the back of a spoon.Do not let the coconut milk boil hard because strong heat can cause it to separate. Add the shrimp and any juices from the plate back to the skillet. Spread them through the sauce in one even layer.
Simmer over medium-low heat for 2 to 3 minutes, stirring once.Remove the skillet from the heat when the shrimp are fully pink, opaque in the center, and shaped like a loose “C.” Stir in the lime juice, chopped cilantro or parsley, and the remaining ½ teaspoon salt.Taste the sauce. Add another 1 teaspoon lime juice or a small pinch of salt when needed. Spoon the Garlic Shrimp in Coconut Milk over warm cooked rice. Garnish with fresh herbs, lime wedges, sliced chili, or green onions.Serve immediately while the sauce is hot and creamy.