Rinse the potatoes and cook in boiling water for about 25 minutes. Drain, cool slightly, peel and cut into thin slices.
Peel the shallots, halve lengthwise and cut into thin columns. Cut the bacon into strips.
Saute the shallots in 1 tablespoon of hot butter. Remove from the heat and set aside.
Spread half of the potato slices in a greased baking dish. Top with shallots and bacon. Slice the cheese and spread half over the shallots and bacon. Add the remaining potato slices. Season each layer with salt and pepper.
Mix the cream and creme fraiche. Season with salt and pepper. Spread the cream mixture over the gratin. Top with the remaining sliced cheese. Bake for about 35-40 minutes at 200°C (approximately 400°F). Remove from the oven and serve immediately.