Crown Roast Of Lamb

• 12 potatoes (new)
• 3 garlic (cloves peeled)
• 3 - diner
• 2 more ribs per person
• 1 crown roast of lamb
• 60 ml olive oil
• 26 gr butter (unsalted)
• 8 gr salt
• 6 gr pepper (freshly ground)
• 3 gr rosemary