There are many nuances when frying; the thinner the patties, the less time they need to cook. Generally, you should preheat the pan and fry the patties over moderate heat for 5-6 minutes on each side. Then, keep them on low heat with the lid on to ensure they are thoroughly cooked and remain juicy. In total, beef or pork patties should be fried for 25-30 minutes, including the steaming time. The juices from the patties should be clear, not pinkish.