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 simmering salted water to cover for 25 minutes; drain. Rinse with cold water; drain again. Slice potatoes about 1/4 inch thick. Sprinkle with salt and pepper. Place half of the potatoes in the bottom of the prepared dish.
Meanwhile, in a large skillet cook bacon over medium heat for 1 minute. Add onion and garlic; cook and stir 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 almost evaporated. Stir in the snipped thyme.
Spoon bacon mixture over potatoes in dish. Top with the remaining potatoes. Pour broth and cream over potato mixture. Cut Brie crosswise into 1/4-inch-thick rectangles and layer on top of potato mixture.
Bake about 40 minutes or until potatoes are tender and cheese is lightly browned. If desired, garnish with fresh thyme sprigs.