In a bowl, mix together the olive oil, red wine vinegar, diced onion, minced garlic, paprika, cumin, salt, and pepper to create the marinade.
Add the meat cubes to the marinade, ensuring they are well coated. Cover the bowl and let it marinate in the refrigerator for at least 2 hours, but ideally overnight for the best flavor.
Preheat your grill to medium-high heat.
Thread the marinated meat cubes onto metal skewers, alternating with pieces of onion if desired.
Grill the skewers for about 10-15 minutes, turning occasionally, until the meat is cooked to your desired doneness.
Serve the shashlik hot with your favorite side dishes like rice, salad, or grilled vegetables.
Enjoy!
