WOW, what a supermarket
The best thing about Harrods is the food hall. You can find absolutelly everything you ever wished to have for cooking tonight. From the most bizarre strawberries to the most common watermelon, going through fresh oysters, lobsters, meat, spanish ham, italian parma ham , etc, etc. Then you can also go and pick up some great french baguette on the bakery, sweet yourself with the only Krispy Cream store in London and finally end up having a marvelous latte in the cafeteria. Oh, the prices? They will bite you a bit, but is worth paying for some luxury food from time to time.