Do It Yourself Recipe: Potatoes Gratin with Coconut Milk. Ingredients & Tools: (1) Coconut (2) Potatoes (3) Garlic & Onions (4) Oven and a big tempered glass Bowl. In this post we are using instead of cow milk, coconut milk which you can make at home as well. You don’t need a cow in your front yard for instances. It’s simple and easy! Some of the nutritional health benefits of Coconut milk and its flesh, it’s highly nutritious and rich in fibre, vitamins C, E, B1, B3, B5 and B6 and minerals including iron, selenium, sodium, calcium, magnesium and phosphorous.