This is a wonderful dish for special occasions. If you’re eating low carb, substitute cauliflower, sliced into flat pieces, and use all cream.
1 large clove garlic, peeled and smashed
1 tablespoon unsalted Kerrygold butter, softened
2 cups organic half-and-half
1/4 cup organic heavy cream
1-1/4 teaspoons sea salt
1/8 teaspoon ground black pepper
Pinch fresh grated nutmeg
Pinch cayenne pepper
2 pounds red potatoes, peeled and sliced 1/8-inch thick or less
(Use a a mandoline slicer or the slicing disk on a food processor)
1/2 cup Gruyère cheese, grated
Adjust oven rack to center position and heat oven to 350 degrees. Butter a 5- to 6-cup gratin dish or shallow baking dish with half the butter.
Bring half-and-half, salt, pepper, nutmeg, cayenne, potatoes, and reserved garlic to boil in medium saucepan over medium-high heat, stirring occasionally with wooden spoon (liquid will just barely cover potatoes). Reduce heat and simmer until liquid thickens, about 2 minutes.
Pour potato mixture into prepared dish; shake dish or use fork to distribute potatoes evenly. Gently press down potatoes until submerged in liquid; dot with remaining butter.
Bake until top is golden brown (basting once or twice during first 45 minutes). At the 45-minute mark, top with the Gruyère. Bake for a total of about 1 hour 15 minutes. Let rest 5 minutes and serve.