Preheat the oven to 425 degrees F. Carefully slice the potatoes into thin slices, leaving a 1/8 inch at the bottom, be careful not to slice all the way through the potato. Place In a 9x13 inch baking dish and gently toss with olive oil, salt, and pepper. Transfer to the oven and roast for 20-25 minutes. Meanwhile, in a medium bowl, combine the cream, garlic, cheese, thyme, and a pinch each of salt and pepper.  Remove the potatoes from the oven and pour the cream over them, arrange the potatoes in a mostly even layer. Place the slices of butter around the potatoes. Return to the oven and roast for another 20-25 minutes, until the sauce thickens and the potatoes are tender. Season with flaky salt just before serving. Enjoy!