Scrambled eggs and omelets are made from yolks and whites mixed together, and are therefore a good fate for fragile, runny lower-quality eggs. These dishes frequently include other ingredients. Cream, butter, milk, water, or oil (used in China) will dilute the egg proteins and produce a tenderer mass when the eggs are carefully cooked; overheating, however, will cause some of the added liquid to separate. Watery vegetables like mushrooms should be precooked to prevent them from weeping into the eggs. Chopped herbs, vegetables, or meats should be warm—not hot or cold—to avoid uneven heating of adjacent egg proteins.