Courtesy of RICARDO.
Butter the inside of the slow cooker.
In a saucepan, bring cream, evaporated milk and garlic to a boil. Cover and let steep for 5 minutes. Discard garlic.
Line the bottom of the cooker with sliced potatoes. Drizzle with some warm cream mixture. Season with salt and pepper. Continue layering with remaining ingredients.
Cover and cook on low for about 5 hours. Turn cooker off. Remove lid and let rest for 30 minutes. Gratin can stay on the warm setting for maximum 1 hour. In this case, you don’t have to let it rest uncovered.