Preheat oven to 190C (375F).

Peel potatoes and slice in half lengthways.

Using a small sharp knife, make cuts 1/4 inch apart from top almost to bottom, across all of the potato halves, being careful not to slice all the way through.

Mix melted butter and olive oil together in a small bowl.

Brush the potato slices liberally with the butter and oil mixture, ensuring it seeps into the cuts.

Sprinkle the potatoes evenly with salt and lemon pepper.

Bake in the preheated oven for about 45 minutes, or until the potatoes are tender and golden brown.