In a large sauté pan on a medium heat, gently sweeten the onion, leek, thyme and salt in the butter for 8 minutes – cover the pan with a lid to prevent them from colouring.
Remove the lid, increase the heat to high and add the sliced bacon.
Continue to cook for 2 minutes until the bacon begins to crisp slightly.
Remove the pan from the heat, add the sliced potatoes, half the Saint Agur® blue cheese and gently mix.
Preheat the grill to high.
Spoon the potato mixture evenly into the oven-proof dish, top with the remaining Saint Agur® blue cheese. Add the enough cream to come halfway up the vegetables in the dish.
Place under the hot grill, reduce the heat to medium and gratinate for 5 minutes, or until golden and bubbling.
Leave to rest for a few minutes before topping with the chopped chives. Serve immediately.