Peel the potatoes. Wash them and dry them with a tea-towel.  Cut them into small cubes.

Heat 4 Tbsp olive oil and 1 Tbsp butter in a large frying pan.

Cook the potatoes for 5 minutes on a medium-high heat, stirring often.

Cut the onions into small pieces. Add them to the potatoes. Cook, while stirring often, for another 5 minutes.

Cut the bacon into short strips and add to the mixture.

Cook for a further 5 minutes.

Take off the heat. Stir in the creme fraiche.

Butter an ovenproof dish and rub the sides with a whole clove of garlic.

Cut the cheese into slices.

Put a layer of the potato mixture into the ovenproof dish, then layer with half the cheese.

Cover with the rest of the potato, and then top with slices of cheese.

Cook at 200°C (400°F) for 15 -20 minutes until the cheese is bubbling and golden.