Heat olive oil in a medium-sized saucepan. Add onion and cook until soft and translucent, about 5 minutes. Add garlic and red peppers; cook 2 to 3 minutes more. Add tomatoes, shrimp, and cilantro and simmer gently until shrimp are opaque, about 5 minutes. Pour coconut milk into the saucepan, add sriracha sauce, and cook until just heated through without boiling. Add lime juice and season with salt and black pepper to taste.
