Start by marinating the chicken. In a bowl, combine the apple cider vinegar, lemon juice, minced garlic, black pepper, oregano, and sea salt to create the tangy marinade. Place the chicken pieces in the marinade, ensuring they are well coated. Cover the bowl and refrigerate for at least 2 hours to allow the flavors to penetrate the meat.

Once the chicken has marinated, preheat your grill to medium-high heat.

Thread the chicken pieces onto skewers, alternating with chunks of onion for added flavor.

Place the skewers on the preheated grill and cook for about 10-12 minutes, turning occasionally to ensure even cooking. The chicken should be nicely charred and cooked through.

Once cooked, remove the skewers from the grill and let them rest for a few minutes before serving.

Serve the chicken shashlik hot with your favorite accompaniments, such as rice, pita bread, or a fresh salad.