Rinse the parsley and cilantro (if using) under cold water to remove grit. Shake or pat dry thoroughly with paper towels or a clean kitchen towel. Remove thick stems from the parsley and cilantro; keep tender stems. Peel the garlic cloves and, if using, peel and quarter the shallot.

Chop or process

For a chunky chimichurri: finely chop the parsley, cilantro, and oregano by hand on a cutting board until they measure about 1 cup packed parsley + 1/2 cup cilantro. Mince the garlic and shallot finely. For a smoother emulsion: pulse the herbs, garlic, shallot, oregano and red chili flakes briefly in a food processor (3–4 short pulses) — avoid pureeing; you want a coarse texture. Scrape down the sides once so everything is evenly cut.

Combine with acid and seasoning

Transfer the chopped herbs and aromatics to a medium bowl. Add the red wine vinegar, lemon juice, smoked or regular paprika (if using), red chili flakes, sea salt, and freshly ground black pepper. Stir to combine and let sit for 2–3 minutes to bloom the flavors.

Incorporate oil

Slowly drizzle the extra-virgin olive oil into the herb mixture while stirring continuously to emulsify slightly. Taste and adjust seasoning: add more salt, pepper, vinegar, or chili flakes to preference.

Rest and store

For best flavor, cover and let the chimichurri rest at room temperature for at least 20–30 minutes before serving to allow the flavors to meld. It can be used immediately if needed. Store leftovers in an airtight container in the refrigerator for up to 5 days; bring to room temperature before serving and stir (the oil may solidify slightly when cold).

Serving suggestions

Serve chimichurri spooned over grilled steak, chicken, fish, roasted vegetables, or use as a condiment for sandwiches and grain bowls. Stir before serving if separated.