When does the cooking time start when boiling frozen vegetables?

The cooking time for frozen vegetables when boiling begins once the water comes to a boil for a second time. This is important for ensuring that the vegetables are cooked evenly and properly. Initially, adding frozen vegetables to boiling water causes the temperature of the water to drop, which can momentarily stop the boiling process. Therefore, the cooking time should not be counted until the water reaches a full boil again after the initial drop in temperature, indicating that it is ready for consistent cooking. This step helps to ensure that the vegetables are not only heated through but also retains their texture and nutritional value.