Articles are difficult. If you are talking about a specific recipe, and therefore specific egg whites, then use the artciles.
As in: Note: The egg whites should be chilled before beating.
If you are talking about general cooking hints, then don't use the article. It's a "universal truth" - Egg white should be chilled before beating.
Your second example is just a bit odd all the way around. The meat is the steak. The steak is the meat. So to say the meat that's prepared for steaks is not logical to me. (Also, chilled, not child.) However, the same thing applies. If you're following a specific recipe, then use "the." Take the meat from the refrigerator and allow to rest for ten minute before...
If you're giving general guidance, the don't use articles. When preparing steaks for grilling...