Courtesy of: I've had this recipe for years, so I don't remember where this one came from or else I'd give credit where credit is due.
1/2 cup vinegar
1/2 cup lemon juice
1 cup vegetable oil
1 cup tomato paste
1/4 cup soy sauce
1/2 tsp pepper
1 tsp parsley
2 tsp salt
1 tsp oregano
1/2 tsp thyme
2 lb round steak, cut into 1" cubes
onion, cut into 1/2" squares OR pear onions
green bell peppers cut into 1" squares
potatoes, parboiled & cut into cubes
Combine first ten ingredients in a large bowl, drop in the round steak cubes & veggies, marinate 3 hours or overnight. You can alternate meat with veggies on skewers OR (due to varied cooking times) you can put all of the steak cubes on their own skewers and all of the veggies on their own skewers. Cook on a grill, baste with leftover marinade, turn skewers often. If everything is cut correctly, these should cook within 10-15 mins. Enjoy!