1) Peel potatoes and cut into 1 inch cubes. Boil potatoes in salted water for 10-12 minutes until very tender and then drain them.
2) Add garlic, butter, milk, and salt and pepper to potatoes and mash or beat with a hand mixer until you have the desired creaminess that you like. Feel free to add more milk if it looks too dry.
3) While your potatoes cook, lay a few strips of thick bacon on a rack over a baking sheet and bake at 400 degrees for 10-15 minutes until the bacon is super-crispy. Let it cool and crumble it.
4) Butter your casserole dish and add mashed potatoes. Top with a drizzle of cream and shredded cheese. Then add crumbled bacon.
5) Use your mandoline or a very steady hand, to slice a peeled potato very thin.
6) Add thin potato slices to top of casserole dish and drizzle with olive oil.
7) Bake at 400 degrees for 20 minutes and then set under the broiler for a few minutes until potatoes are nice and browned.
8) Let cool for a few minutes and serve immediately!