Place shrimp in a gallon-size resealable plastic bag, and add 1/2 teaspoon kosher salt, 1/8 teaspoon black pepper and cayenne. Mix well and refrigerate.
In a deep skillet or sauté pan over medium-high heat, combine oil and chilies and stir 1 to 2 minutes. Add 1/4 teaspoon black pepper and cook for 1 minute longer. Add ginger, onion, 1 tablespoon plus 1 teaspoon kosher salt and sauté until onion is soft and translucent, 5 to 8 minutes. Add garlic, ground coriander and turmeric and sauté until fragrant, about 1 minute.
Reduce heat to medium-low and add tomatoes. Stir, scraping sides and bottom of pot, for 1 minute. Increase heat to medium-high and simmer for 5 minutes, stirring often.
Stir in curry powder and cook for 1 minute. Add coconut milk, bring to a boil, and add shrimp. Bring to a simmer and cook until shrimp are opaque, 2 to 3 minutes. Stir in cilantro. If desired, serve with rice.