The Most Unexpected Sauce on This Site
Chimichurri is the classic Argentinian herb sauce for grilled beef. Folded into mayonnaise, it becomes something different — the bright acidity and fresh herb character of chimichurri, moderated by the fat of the mayo into a dipping sauce that clings to fried food in a way that straight chimichurri can't. The result is the most herbaceous and fresh-tasting sauce in the lineup, and it works surprisingly well against the hot, savory crust of a finger steak.
This is not a traditional Idaho pairing. Fry sauce is traditional. This is what happens when you take a dish built around beef and apply a sauce that has always worked with beef, just in a different context. The garlic, parsley, oregano, and red wine vinegar in the chimichurri base are all classic beef accompaniments. The mayo gives them the texture they need to work as a dipping sauce rather than a drizzle.
It takes about ten minutes to make and tastes best after a 20-minute rest. Make it while the beef is marinating or while the oil is heating up.
Chimichurri Mayo
- 1/2 cup fresh flat-leaf parsley, finely chopped (packed)
- 2 tablespoons fresh oregano leaves, finely chopped (or 1 tsp dried)
- 3 garlic cloves, minced or grated
- 2 tablespoons red wine vinegar
- 2 tablespoons olive oil
- 1/4 teaspoon red pepper flakes
- 1/4 teaspoon kosher salt
- 1/4 teaspoon black pepper
- 1/3 cup full-fat mayonnaise
- 1 teaspoon fresh lemon juice
- Combine the parsley, oregano, garlic, red wine vinegar, olive oil, red pepper flakes, salt, and pepper in a small bowl. Stir well until combined. This is the chimichurri base — taste it now and adjust if needed. It should be bright, garlicky, and slightly sharp.
- In a separate bowl, whisk the mayonnaise and lemon juice together until smooth.
- Add half the chimichurri to the mayo and fold to combine. Taste. Add more chimichurri to reach the herb level you want. The ratio is adjustable — more chimichurri makes it brighter and more herbal, less makes it creamier and more subdued.
- Cover and rest at room temperature for 20 minutes before serving, or refrigerate for up to 2 hours. The garlic mellows and the herbs infuse the mayo during this rest — don't skip it.
On fresh vs. dried herbs: Fresh flat-leaf parsley is the right call here. Curly parsley has less flavor and a different texture when chopped fine. Dried parsley produces a muddy, flat sauce. The oregano can be dried if fresh isn't available — the difference is less significant than with the parsley.
Storage: Keeps covered in the refrigerator for up to 3 days. The garlic flavor intensifies over time. By day two it's noticeably more pungent, which some people prefer.
Why This Works With Beef
The flavor profile of chimichurri — garlic, parsley, acid, a background of dried herb — is one of the most natural pairings for beef that exists. It's the sauce Argentina built an entire beef culture around. Folding it into mayonnaise is not traditional, but it solves the only problem chimichurri has as a dipping sauce: it's too thin to coat a fried strip properly and the oil tends to separate out quickly.
The mayo emulsifies everything. The garlic and parsley stay suspended in the sauce instead of pooling at the bottom of the bowl. It coats each strip in a way that straight chimichurri doesn't. The acidity of the red wine vinegar is still present — you can taste it clearly — but it's balanced by the fat of the mayo rather than hitting sharp and immediate.
For the classic recipe, this is a worthy alternative to fry sauce when you want something brighter and more herbal. For the buttermilk version, the acidity in the chimichurri base complements the tang in the batter in a way that richer sauces can't.
Have Questions?
Common questions about sauces and technique are covered on the Finger Steak FAQ page.