Cooking times for frozen sausages in a deep fat fryer vary depending on the size of the sausages. Generally, it takes about 5 minutes to cook small-sized sausages and 8 minutes for larger ones. It is important to ensure that the oil is hot enough before adding the sausages as this will help them cook evenly and prevent them from sticking together. Once they are golden brown, remove them from the fryer with a slotted spoon or tongs and place them onto kitchen paper towels to absorb any excess oil. Serve immediately while still hot.