If desired, trim fat from steaks. Score skirt or flank steak on both sides by making shallow cuts at 1-inch intervals in a diamond pattern. Place all meats in a 2-gallon resealable plastic bag set in a large shallow dish. For marinade, in a small bowl, combine salad dressing, garlic, parsley, oregano, salt, and pepper. Pour marinade over the meat; seal bag. Turn bag to coat meat. Marinate in the refrigerator for 4 to 8 hours, turning bag occasionally. Drain meat, discarding marinade. Pat meat dry with paper towels.
For a charcoal grill, grill meat on the rack of an uncovered grill directly over medium coals until meat reaches desired doneness, turning meat once halfway through grilling. Allow 17 to 21 minutes for skirt steak, 10 to 15 minutes for shell and porterhouse steaks, and 3 to 5 minutes for sausages. (For a gas grill, preheat grill. Reduce heat to medium. Place meats on grill rack over heat. Cover; grill as above.) When meats are done (145 degrees F for medium-rare; 160 degrees F for medium doneness) let stand several minutes before slicing. Serve meats with Chimichurri. Makes 10 servings.
In a medium bowl, combine parsley, garlic, oregano, crushed red pepper, and salt. Add oil and vinegar. Using a fork, toss to combine. Serve sauce immediately or cover and chill for up to 3 days. Makes 1-1/2 cups.