Steak Kebabs with Chimichurri

Name: Steak Kebabs with Chimichurri
Ingredients: 1 3/4 lbs. Sirloin steak (thicker steaks), (diced into 1-inch cubes); 1 large red onion, (chopped into chunks); 1 lb. cherry tomatoes or grape tomatoes (look for larger ones); 2 small zucchini, (sliced 1/4-inch thick); Salt and freshly ground black pepper; Oil for brushing; 1/3 cup olive oil; 1/2 cup (packed) fresh parsley ((no thick stems)); 1/4 cup (packed) fresh cilantro ((no thick stems)); 1 tsp dried oregano; 1 1/2 Tbsp red wine vinegar; 1 Tbsp fresh lemon juice; 1 1/2 tsp minced garlic ((1 large clove))