Preheat oven to 350 degrees F. Grease a 2-quart au gratin dish or rectangular baking dish; set aside. In a covered Dutch oven, cook potatoes in enough boiling, salted water to cover for 25 minutes; drain. Rinse with cold water; drain again. Slice potatoes. Sprinkle with salt and pepper. Place half of the potatoes in the bottom of the prepared au gratin dish.
Meanwhile, in a large skillet, cook bacon over medium heat for 1 minute. Add onion and garlic; cook about 5 minutes or until bacon is crisp and onion is tender. Drain off fat. Carefully add wine to bacon mixture. Simmer, uncovered, until wine is nearly evaporated. Stir in thyme.
Spoon bacon mixture over potatoes in dish. Top with the remaining potatoes. Pour broth and cream over potato mixture.
Using a sharp knife, score both sides of cheese rounds in a diamond pattern by making shallow diagonal cuts at 1-inch intervals. Cut rounds in half horizontally, then in half crosswise. Arrange cheese, rind sides up, on top of potato mixture.
Bake, uncovered, about 40 minutes or until potatoes are tender and cheese is lightly browned.