Name two common emulsifiers used in cooking.

Choosing egg yolks and mustard as common emulsifiers in cooking highlights their critical role in creating stable mixtures of ingredients that typically do not combine well, such as oil and water.

Egg yolks contain lecithin, a natural emulsifier that helps bind fats and water, making them essential for sauces like mayonnaise and hollandaise. Similarly, mustard contains compounds that facilitate the emulsification process, enhancing the stability and texture of dressings and sauces. Together, these emulsifiers allow chefs to create smooth, cohesive products that have a desirable mouthfeel and appearance.

The other options listed do not serve the same function. Pepper and salt are flavor enhancers rather than emulsifiers, while oil and vinegar are often used together in dressings, but vinegar is not an emulsifier by itself. Honey and sugar, primarily sweeteners, do not possess emulsifying properties either. Thus, egg yolks and mustard are indeed the correct choice for common emulsifiers used in cooking.