Heat oven to 200C/180C fan/gas 6. Rinse and dry the unpeeled new potatoes. Put 2-3 tbsp duck fat or olive oil in a roasting tin and put in oven for 10 mins to melt. Strip leaves from rosemary, oregano and sage and stir into tin with seasoning.
Add potatoes and toss well. Roast for 40-50 mins, shaking tin a couple of times, until potatoes are crisp and tender. Sprinkle with sea salt and serve.