How should cut onions be collected during preparation?

Collecting cut onions in a white tub is the most suitable method during preparation for several reasons. Firstly, using a tub allows for easy containment and prevents spills, which can be crucial in a busy kitchen environment where efficiency is key. The tub's design facilitates stacking and organizing, making it easier to manage multiple ingredients simultaneously.

Moreover, a white tub generally aligns with food safety standards, as it is often made from food-safe materials that won't react with the onions or harbor bacteria. This choice helps in maintaining the quality and safety of the food being prepared. Additionally, using a tub provides adequate space for a larger quantity of onions without risk of them rolling off or contaminating other surfaces, which can occur if they are placed on a cutting board or a plate.

In contrast, while other options like a plastic bag or plate might offer some level of containment, they do not provide the same level of stability and organization that a tub does. A cutting board typically serves as a work surface, which is not ideal for storing cut ingredients. Therefore, using a white tub is the best practice for collecting cut onions effectively and safely.