Chimichurri
Try it on steak. Try it on fries. Try it on empanadas. Absolute classic.

Ingredients
1/2 cup extra virgin olive oil
2 tablespoons red wine vinegar
1/2 cup flat parsley, finely chopped
1/4 cup cilantro, finely chopped
3-4 cloves garlic, minced
2 small red chilis, finely chopped or crushed red pepper flakes to taste
3/4 teaspoon dried oregano
Salt to taste
Pepper to taste
Instructions
Finely chop parsley and cilantro and mince garlic.
In a small to medium bowl, combine ingredients (olive oil, red wine vinegar, parsley, 1/2 of garlic, chilis or crushed red pepper flakes, oregano)
Whisk together
Add salt and pepper to taste
Let sit for approximately 5-10 minutes, and taste again, adjusting garlic (you should have some remaining), salt, and pepper to taste.
Nugget
You can keep parsley, cilantro and other fresh herbs fresh for at least a week or two by cutting off 1 inch of the stems after purchasing and keeping in a mason jar or other vessel with water. Cover in the fridge with a plastic covering (Ziploc bags work fine) to keep them humid and fresh.