Preheat your oven to 375°F and lightly grease a 9x13 inch baking dish (or similar size casserole). While the oven heats, slice the potatoes into thin 1/8-inch rounds—I recommend using a mandoline slicer for even thickness, which ensures uniform cooking and the best creamy texture. Mince the garlic fresh and have all your spices measured and ready: thyme, salt, pepper, nutmeg, and cayenne pepper.

In a large pot, combine the cream and milk, then bring to a gentle boil over medium-high heat. Once steaming, reduce the heat to medium-low and add the minced garlic, thyme, salt, pepper, nutmeg, and cayenne pepper. Simmer this mixture for 10-15 minutes, stirring occasionally, to allow the flavors to infuse and meld together. I like to let it simmer a bit longer to really develop that garlic flavor—it's the foundation of the dish, so don't rush it.

Starting with the sliced potatoes from Step 1, layer them in the greased baking dish in three stages. Add 1/3 of the potatoes as the first layer, then sprinkle 1/3 of the cheddar cheese over them. Repeat with another 1/3 of potatoes and 1/3 of cheese. Finally, add the remaining potatoes on top as the final layer. Pour the warm cream sauce from Step 2 evenly over all the layers, ensuring the potatoes are well covered. The sauce will seep down and cook the potatoes from within.

Cover the baking dish tightly with foil or a lid and place it in the preheated 375°F oven. Bake for 20 minutes covered. This traps the steam and gently cooks the potatoes through while the cheese and cream meld together. The foil keeps the top from browning too quickly while the filling cooks.

Carefully remove the baking dish from the oven and lift off the foil. Sprinkle the remaining cheddar cheese evenly over the top of the potatoes. Return the dish to the oven uncovered and bake for another 10 minutes until the cheese melts, becomes bubbly, and develops a light golden color on top.

Remove the baking dish from the oven and let it cool for 10 minutes before serving. This resting period allows the cream sauce to set slightly, making the scalloped potatoes easier to scoop and serve while still staying moist and creamy. The texture will be perfect—neither too loose nor too thick.