Preheat oven to 180C/350F/Gas 4.
Peel and slice the potatoes lengthways. Place in roasting tray.
Cover with olive oil, water, lemon juice and oregano.
Season to taste and mix.
Place the baking tray in the oven for 1½ hours. If cooking with Thyme, Sage and Garlic Roast Chicken, put the tray under the chicken to catch all the juices.