This is my favorite summer grilling dish. I marinate with the sauce and reserve some for pouring over the meat when it is done:

Steak with chimichurri sauce:

Get yourself:
skirt steak or flank steak
3 garlic cloves
1/2 C olive oil
3 tablespoons red wine vinegar
Small bunch of parsley
small bunch of oregano
1/2 teaspoon salt
pepper to taste
Juice of a lime

Do:
Put all ingredients (besides the steak) in a food processor and pulse until combined.

marinate meat for up to one day but at least 1 hour, with half of mixture.
heat grill to high
grill marinated meat 5 minutes per side

let it rest covered with tin foil for 5 minutes before cutting into slices and serving with the rest of the sauce!