This recipe is traditionally made with a combination of parsley and cilantro. I don't always have both and the hubby and I actually prefer it with all cilantro sometimes. Feel free to change it up to suit your taste.
1 C Cilantro
1/2 C Olive oil
1/3 C Red wine vinegar
1 T Minced garlic or to taste
Generous squeeze of lime
Salt and pepper to taste
Put ingredients in a blender and puree until almost smooth. Try your own variations and see how you like it best. At my house we like to add a lot of lime to the mix although it is not a traditional ingredient. Many recipes call for a good pinch of red pepper flakes, I usually omit this to suit my mother-in-law's taste. It is fantastic on all meats and even potatoes or yucca.
Grocery Tip: If you can find a good chimichurri (very few bottled are any good) that is pre-made at the market, pick it up and save yourself a few minutes, it's nice to have on hand.