The most crucial part of shashlik is the marinade. Using vinegar or lemon juice helps denature the proteins in the meat, making it incredibly tender after grilling. Cut the meat into sufficiently large cubes (about 4x4 cm) so that it does not dry out during grilling.
When grilling, the meat is not turned until a nice crust forms on the bottom side. Shashlik is traditionally grilled over charcoal, not an open flame.
Trim the pork and cut it into cubes approximately 4x4 cm.
In a large bowl, mix the diced meat, onion rings, vinegar/lemon juice, oil, salt, and pepper.
Thoroughly mix the meat by hand (ideally using gloves) so that all ingredients are evenly distributed. Squeeze the onion to release its juices.
Cover the meat and let it marinate in the refrigerator for at least 12 hours, ideally 24 hours. The longer, the more tender and flavourful the meat will be.
Remove the meat from the refrigerator before grilling. Skewer the meat cubes onto metal or wooden (pre-soaked) skewers. Press the meat firmly together on the skewer, but not too tightly so that heat can circulate.
Do not skewer the onion from the marinade, as it would burn quickly. The onion can be used to line the serving plate for the finished shashlik.
Heat the grill to medium-hot coals (not an open flame). Place the skewers over the heat and grill.
Turn the meat every 5-7 minutes until it is nicely browned on all sides and cooked through and juicy inside (the internal temperature should reach 71 °C / 160 °F). The total grilling time is approximately 20-30 minutes.
Remove the finished shashlik from the skewers. Serve immediately, ideally on a base of fresh onion and sprinkled with chopped herbs (dill, parsley). Freshly baked bread (e.g., Lavash) and pickles are suitable sides.