Preheat oven to 350°F.

Using a mandoline (or a very sharp knife), slice potatoes very thinly.

Place slices into a large or several small single-serve ramekins. Cut the potato slices in order to fit if necessary. Pack in well, but do not over pack - you need to leave room to add in the cheese sauce.

Place ramekin(s) on a baking sheet. Set aside briefly.

Add 1 tablespoon butter to a small saucepan. Place over low heat and melt.

Add garlic. Sauté garlic for 1 minute.

Add flour. Whisk to form a roux.

Add heavy cream. Whisk and mix until the roux has dissolved.

Add all 3 cheeses. Simmer, stirring occasionally, for 5 to 8 minutes, until all cheese has melted.

Carefully pour prepared cheese sauce over potatoes in ramekin(s). Fill pretty close to the top - but leaving space to add the topping.

Place potato chips and fried onions in a food processor (To save time, do this while the sauce is cooking). Pulse until the mixture is crumbly.

Place crumbles into a medium bowl.

In another small pan over low heat or in the microwave, melt remaining 2 tablespoons of butter.

Pour butter over crumbles. Mix well.

Sprinkle crumbles over each ramekin. Be sure to cover well (See photo above).

Place entire pan with ramekin(s) into preheated oven.

Bake 30 to 40 minutes until the topping is golden brown and the potatoes are tender.

Serve hot - But be sure to warn your guests that the ramekins are hot, too, especially if using single serve ramekins.