*Melt butter in large dutch oven over medium-high heat until foaming subsides, about 1 minute *Add onion and saute until it turns soft and begins to brown, about 4 minutes *Add garlic and saute until fragrant, about 30 seconds *Add cream, milk, thyme, bay leaves, salt, pepper, and potatoes. Bring to simmer. Cover, adjusting heat as necessary to maintain light simmer. Cook until potatoes are almost tender, about 15 minutes *Remove and discard thyme sprigs and bay leaves. *Transfer potato mixture to a 3-quart casserole and sprinkle with cheese *Bake at 350 until cream has thickened and is bubbling around sides and top is golden brown, about 20 minutes. Cool for 5 minutes before serving. **Note: For the fastest and most consistent results, slice the potatoes in a food processor or use a mandoline. At exactly 1/8 inch, the potatoes hold their shape yet remain flexible enough to form tight, cohesive layers. ** I use more cheese than the 1 cup called for because my husband likes his scalloped potatoes really cheesey! I add a cup of cheese to the milk mixture as the potatoes simmer. Also, I use only 2 sprigs of thyme and 1 bay leaf for a milder flavor.