Place first 8 ingredients in a food processor; process until smooth. With processor on, slowly pour olive oil through food chute; process until well blended.
Pour chimichurri sauce into a small bowl; set aside.
. Prepare grill.
Sprinkle steaks with 1/4 teaspoon salt and 1/4 teaspoon black pepper.
Place steaks on grill rack coated with cooking spray; grill 5 minutes on each side or until desired degree of doneness.