Flank Steak with Chimichurri

Ingredients

• 1 cup fresh flat-leaf parsley, packed and trimmed of thick stems
• 1/2 cup cilantro, packed and trimmed of thick stems
• 3-4 garlic cloves
• 3 tablespoons fresh oregano leaves (can sub with 2 teaspoons of dried oregano)
• 1/2-3/4 cup extra-virgin olive oil
• 1/4 cup red onion or shallots, finely diced
• 2 jalapeños, chopped (optional)
• 1/4 tablespoon red or white wine vinegar
• 3/4 teaspoon sea salt (or more to taste)
• 1/4 teaspoon freshly ground black pepper (or more to taste)
• 2 small red chilli peppers, sliced
• 2.2 lb flank steak
• 1 teaspoon salt
• 1 teaspoon ground black pepper