1️⃣ Preheat your oven to 325°F (163°C). 🔥

2️⃣ In a small saucepan, add the heavy cream, kosher salt, and minced garlic. Bring the mixture to a simmer over low heat and cook for 5 minutes to infuse the garlic flavor into the cream. Remove from heat and set aside. 🍶🧄

3️⃣ Using a mandoline slicer, thinly slice the potatoes to 1/8-inch thickness. 🥔🔪

4️⃣ In a 12-inch cast iron pan, melt the butter over low heat and add the diced shallot. Sauté for 5 minutes until the shallots are caramelized. 🧈🧅

5️⃣ Arrange the sliced potatoes in a spiral pattern over the cooked shallots in the cast iron pan. Pour the garlic-infused cream mixture evenly over the potatoes. 🥔🌀🍶

6️⃣ Cover the cast iron pan tightly with aluminum foil. Place the pan in the preheated oven and bake for 1 hour and 15 minutes. ⏳

7️⃣ Remove the pan from the oven and increase the oven temperature to broil. 🔥

8️⃣ Sprinkle the grated Gruyere and Parmesan cheeses over the top of the potatoes. Add the fresh thyme. 🌿🧀

9️⃣ Place the pan back in the oven and broil for 5 minutes, until the cheese is crispy and bubbling. 🧀🔥

🔟 Remove from the oven and serve warm. Enjoy! 😋

Storage Tip: You can store leftovers in the fridge and reheat them the next day. ❄️➡️🔥