Whenever I try to eat an egg sunny side up on a sandwich, I end up with egg all over my sandwich hand as soon as I get to the yolk. Is there a technique that prevents this, or are sunny-side-up sandwiches just not compatible with clean hands?
My technique, which whilst not always perfect, has quite a good success rate (and I usually have HP Sauce [1] on my sandwich, which mean the leakage possibilities are increased), is this.
First you need to hold the sandwich delicately, and vertically, at the bottom of the sandwich pressing the bottom edge of the crust together. This ensures that when the yolk breach occurs gravity will ensure the the golden goodness flows down into the sandwich. The next most important thing is to own the breach. Don't allow this to happen when you are biting the sandwich, as by then you won't have any control over the flooding out. I tend to force the breach before I take the first bite. This has 2 advantages as I see it:
I clasp the bottom edge, closet to the floor firmly with my thumbs and little fingers, so the leakage possibilities from this end are minimal. Then allow the sandwich to open slightly to form a narrow 'V'. Next force the breach. As soon as you breach the egg be prepared. You need to direct the flow to one side by tilting the sandwich. As the flow approaches the lower side of the sandwich start to close it up on that side, forcing the flow toward the top edge. As the flow gets towards the top, tilt the sandwich the other way and repeat the process, distributing the flow throughout the sandwich.
This should be good enough to avoid any large spillage, but if the amount of flow is still significant then I tend to force it up to a top corner and 'attack' the overflow with a single large bite.
The final stage is to hold the sandwich vertically so that the bottom and side edges are not parallel with the ground, but form a 'V' and eat from the top '^' corner. This allows you to seal both the bottom edges with your hands and minimises the chances of a leak.
As I said it's not always perfect but works quite well.
[1] http://en.wikipedia.org/wiki/HP_SauceIn my house, there are two options for this problem, both quite similar:
Eventually, it needs ot be said that getting a little less sterile is part of the fun of these sandwiches. Just don't wear any expensive trousers while you're doing it, that's all.