In a food processor, mix vinegar, garlic, parsley, oregano, cilantro, hot pepper flakes and salt. Pulse until herbs are chopped but not liquefied.
Pour in oil and pulse briefly just until combined.
Scrape into small dish.
Cover and let rest for 30 minutes before serving over grilled steak, burgers or chicken.
Store extras for up to 3 days in the refrigerator.
Makes 3/4 cup
Notes
Use as a marinade. Split the sauce in half, use half to marinade red meat for 2 hours and chicken for 30 minutes (discard marinade after use). Serve remainder of sauce with cooked meat. Chimichurri is best made with fresh herbs, do not substitute fresh parsley with dried. If necessary, 1 Tbsp of dried oregano can be used - allow to soak to ensure oregano fully re-hydrates.