In an ovenproof pan, over medium heat, warm some olive oil and butter then add the garlic, potatoes and rosemary sprigs.
Sear the potatoes without turning them for 3 -4 minutes until the butter is foaming and golden brown.
Turn them over and season with salt and pepper.
Pour in the stock and cover with a lid. Simmer for 15 -20 minutes until cooked through. Keep warm until needed.
Serve warm with the glazed stock over.