1. In small sauce pot, combine the milk, coconut, sugar, and salt. Stir with a wooden spoon over medium heat. Continue simmering until it has reduced to by about a fourth. Cover and allow to steep for one hour. After one hour, strain the coconut milk into a measuring cup. Reheat milk mixture over medium-low heat.
2. In a separate bowl, whisk egg yolks. Once milk mixture is hot, temper the yolks by adding half of the mixture into the eggs, whisking constantly. Return mixture to saucepan, and heat until thickened.
3. Pour sweetened condensed milk, lime juice and zest into a large mixing bowl, over an ice bath. Strain custard into the cream, stirring until cooled. Add coconut extract, stir, and place in refrigerator until thoroughly chilled, about 5 hours or overnight.
4. Once chilled, add to ice cream maker and follow manufacturer’s instructions.