Greek Lemon Potatoes

• 2 pounds potatoes
• 4 tablespoons butter
• juice of ½

Peel potatoes and cut them in quarters lengthwise. Place in a gratin dish or shallow casserole with butter, the juice of ¼ lemon and ½ crumbled beef stock cube, and season to taste with salt and freshly ground black pepper. Cook in a moderately hot oven (400°-M5) for 15 minutes. Turn potatoes over and return to oven for 15 minutes more. Remove excess fat from dish; add remaining lemon ju