In a large bowl, combine the vegetable oil, red wine vinegar, lemon juice, ground coriander, ground cumin, paprika, dried thyme, dried oregano, black pepper, and salt.
Add the chopped onion and minced garlic to the bowl and mix well.
Add the meat cubes and toss to coat them evenly with the marinade.
Cover the bowl and refrigerate for at least 2 hours, or overnight for best results.
Preheat your grill to medium-high heat.
Thread the marinated meat cubes onto skewers, packing them closely together.
Place the skewers on the grill and cook for about 10-15 minutes, turning occasionally, until the meat is cooked through and has a nice charred exterior. The internal temperature should reach at least 145째F (63째C) for pork or 160째F (71째C) for lamb.
If using wooden skewers, soak them in water for 30 minutes before grilling to prevent burning.
Remove the skewers from the grill and let the Mtsvadi rest for a few minutes.
Garnish with chopped fresh parsley and serve with lemon wedges on the side.
Enjoy your meal!