The zest is the colored part of the lemon and lime rind. Use a vegetable peeler to remove it, then chop it finely.Peel shrimp and butterfly by cutting lengthwise so that shrimp open like a book and lie almost flat. Don't cut them in half.Combine lemon and lime zest, jalapeno, and white peppercorns and set aside.Combine lemon and lime juice with brown sugar in a small saucepan and simmer until 3 tablespoons are left. Add the salt and zest mixture. Cook for one more minute and remove from heat. Moisten with 1 tablespoon olive oil and let cool.Press the mixture onto both sides of the butterflied shrimp, then sear in olive oil. Cook for one minute, then add the starfruit and ginger. Add the rum, swirl it around in the pan for a few seconds, and serve.