We served this fresh-herb Argentinian sauce over grilled steak marinaded in chimichurri as well.
1 shallot, finely chopped
3–4 garlic cloves, thinly sliced or finely chopped
1/2 cup red wine vinegar
1 tsp. salt
1/2 cup finely chopped cilantro
1/2 cup finely chopped flat-leaf parsley
2 tbsp. finely chopped oregano
3/4 cup extra-virgin olive oil
Combine shallot, garlic, vinegar, and salt in a medium bowl. Stir in cilantro, parsley, and oregano, then whisk in oil.
Place meat in a dish and coat with some of the chimichurri. Cover and chill at least 3 hours or up to overnight.
Keep extra chimichurri and place in a small bowl; season with salt and reserve as sauce.
Remove meat from marinade, pat dry, and grill. Spoon reserved chimichurri over grilled meat.