Tenderizing steak after it has been cooked is challenging since the cooking process has already denatured the proteins and caused moisture loss. However, there are a few techniques you can try to improve the tenderness:
Marinating: While marinating before cooking is more effective, you can still try marinating the cooked steak for a short period. Use an acidic marinade containing ingredients like lemon juice, vinegar, or yogurt. The acid can help break down some of the proteins and potentially improve tenderness. Keep in mind that marinating after cooking may not have a significant impact on tenderizing the steak.
Slicing thinly: If the steak is cooked and still tough, slicing it thinly against the grain can help make it easier to chew. This method can help break up the muscle fibers and reduce the perceived toughness of the meat.
Moist heat cooking: If the steak is particularly tough, you can try incorporating moist heat cooking methods. For example, you could simmer the cooked steak in a flavorful liquid or sauce for a period of time. The additional moisture and low heat can potentially help soften the meat slightly.
Mechanical tenderization: Using a meat mallet or a meat tenderizer tool, you can physically pound the cooked steak. Gently pound both sides of the meat to break down the muscle fibers and make it more tender. However, this method is less effective on cooked steak compared to tenderizing raw meat.
Keep in mind that none of these techniques will completely transform a tough, overcooked steak into a perfectly tender one. It's best to focus on proper cooking techniques and using cuts of meat suitable for the desired level of tenderness to achieve the best results.