Steak Kebab dengan Chimichurri

Bahan-bahan (6 porsi)

• 1 1/4 pounds daging sapi ((sirloin atau Angus) dipotong dadu berukuran 1 inci)
• fresh ground pepper
• 1 1/4 tsp garam halal
• 1 large red onion (cut into large chunks)
• 18 tomat ceri
• 6 tusuk sate bambu (direndam air selama 1 jam)
• 2 packed tbsp parsley (finely chopped (no stems))
• 2 packed tbsp chopped cilantro
• 2 tbsp red onion (finely chopped)
• 1 clove garlic (minced)
• 2 tbsp extra virgin olive oil
• 2 tbsp apple cider vinegar
• 1 tbsp air
• 1/4 tsp garam halal
• 1/8 tsp fresh black pepper
• 1/8 tsp crushed red pepper flakes (or more to taste)