Roughly chop two of the three scallions and peel garlic, as well as ginger. Heat vegetable oil in a pot and sauté with the spices on medium heat for about a minute.
Add coconut milk and 350ml water and bring to a light boil. Put in the chicken breasts and let simmer on lowest heat point for 10-12 minutes.
Meanwhile, chop remaining scallion and put in a bowl. Squeeze half an orange and add juice along with rice vinegar and a generous amount of pepper. Let marinate until chicken is poached.
Take out chicken breasts and slice. Serve with some of the poaching liquid and jasmine rice. Top with marinated scallions and cilantro.