To make the blue cheese dressing, using a large mixing bowl, add in the blue cheese then break up with a fork until it becomes coarse chunks. Add in the rest of the ingredients (aside from the salt, parsley, and pepper) on the list, then mix properly to combine. Let the mixture sit for a few minutes to develop flavour, season with salt and pepper to taste, add in the parsley then mix everything.
Using a small mixing bowl, add in 1 tablespoon of olive oil, Worcestershire sauce, and Montreal steak seasoning then mix properly to combine. This makes the marinade. Add the steak into the bowl containing the marinade then toss to coat. Place the steak and its marinade into a sealed bag then marinate in the refrigerator for about one hour.
Place a skillet pan or a grill pan over medium heat then add in the rest of the oil. Once the oil is hot, add in the marinated steak and cook for about three to four minutes on both sides until it becomes brown in colour. Once cooked, place in a plate to cool for about five minutes.
Next, using a large mixing bowl, add in the chopped lettuce, blue cheese crumbles, green onion, and chopped cucumber then toss to combine. Use a sharp knife to slice the steak then add to the bowl containing the salad. Season the meal with salt and pepper to taste then serve with the blue cheese dressing.