The Serpentine Bar and Kitchen in Hyde Park had poached eggs with avocado and tomato (I asked for no bread), with a pot of tea and fresh squeezed orange juice, and a table looking out over the lake. Not too shabby.
Our hotel (the Ascot Mayfair) had a breakfast (not included in the price of the room) that was fairly typical of European hotels. There was a buffet with deli meat, cheese, yogurt, fruit, and of course, little packets of Nutella, that sweet goodness that is ubiquitous in Europe and rare in the US. They would also boil you an egg, hard or soft.
Hotel breakfast at the Mitre Carlton (directly across the street from Hampton Court -- great location) was similar, but with eggs any style (I had poached). Amusingly, the room service menu at the Mitre Carlton said that gluten free items are marked "GF," but not a single item was, in fact, marked "GF"!