There's nothing tastier than a good gratin dauphinois. The advantage of this potato-based dish is that it is a wonderful side dish for many meals: roast chicken, rib steak, leg of lamb, baked fish, or simply plain, as it is so hearty.It consists of potatoes, milk, cream, garlic and nutmeg. Our mouths are already watering!However, making a gratin dauphinois at home is not always easy, and its delicacy sometimes comes down to detail. Check out all our tips for a delicious meal!1. Replace milk with creamIf the traditional recipe calls for whole milk and cream to infuse and cook the potatoes, our trick is to use only fresh whole cream. Your gratin will be very tasty and your potatoes very smooth. That's all we expect from this dish!2. Cut the potatoes to the right sizePotatoes for gratin dauphinois do not require pre-cooking. To do this, they must not be cut too thin, at the risk of them turning into mash potatoes, or too thick, at the risk of being undercooked. The ideal is to use a mandolin (be careful with your fingers) to cut your potatoes into regular 5 mm slices.3. Do not rinse the potatoesWhile potatoes usually require a little washing before cooking, it is better to skip this step for the gratin dauphinois. Indeed, the starch they contain will give body to the dish and make it bind.4. Opt for a long cooking timeDon't be in a hurry to taste your gratin dauphinois. It will take a few hours for the potatoes to cook slowly and for the cream to thicken. The ideal time? 3 hours at 120°C. You can pre-cook your gratin and finish cooking just before serving.5. Don't add cheese (really, don't)If some recipes recommend adding cheese to the gratin between the potatoes on top, be aware that this is optional. The thick cream mixed with the starchy potatoes will form a very melt-in-the-mouth thick mixture. The cream will form a thin, golden and crispy crust on the top. Try it, you won't even notice the absence of cheese!