I have found that there are two completely distinct ways of adding meat to a bowl of noodle soup, both equally enticing. Not that these are the only way you can do it, of course. Meat can be fried and added, braised, long cooked right in the soup. These two methods are for adding it at the last minute.
What you see here is a pork shoulder chop that was seasoned, dipped in egg, then coarse dry bread crumbs, fried in olive oil and butter, then let cool. The crumbs keep all the moisture in the meat, and as you can see I like it a little rare. The next day four thin sliced were made and it was just placed in the very hot soup to heat through. It tastes so much better in the soup than on its own. The technique is more or less Japanese, and the way it's served. The point is that the pork is still really succulent and tender.
But you can also take the exact same cut of meat, slice it thin raw, season with soy sauce, ginger, maybe some sesame oil let it marinate with a generous teaspoon of rice starch, or some other kind of starch. The prep is exactly as you would do for a stir fry. But instead, just lower the slices into the pot of soup and simmer for a couple of minutes. The starch keeps all the moisture inside the meat. It would just seep out into the broth otherwise. This technique is derived (again more or less) from Chinese cuisine.
I'm not sure which I like better, but both are infinitely more interesting than just boiling meat in soup, which if a delicate cut, just ruins it. By the way, the same can be done with chicken breast or very lean beef. Try one of these techniques the next time you do regular chicken soup, for example.
