Preheat oven to 400°F. Spread the potatoes in a single layer in a 9" x 13" baking dish and pour the oil over them. Add the garlic, dried oregano, salt and pepper to taste and toss well to coat with the oil.
Roast the potatoes for 15 minutes. Add the stock, toss and bake for 10 minutes more. Add the lemon juice, toss and bake for 10 to 15 minutes more, or until the potatoes are golden and cooked through.
If you like, sprinkle with fresh oregano.