Chimichurri Sauce for Steak and Veggies

Name: Chimichurri Sauce for Steak and Veggies
Ingredients: 1.5 lb flank steak grass-fed optional; 1 cup parsley stems removed; 2 shallots or white onion cut in half; 2 cloves garlic peeled; 2 tbsp dried oregano; 0.5 cup olive oil; 0.25 cup red wine vinegar