Salad dressing? What's
that?
Seriously, when I do indulge in salad dressing at home, I either just toss some olive oil and vinegar over the greens or use brand name Litehouse Blue Cheese. It's found near Marie's, in stores that carry it. Not all do. I try for canola oil as main ingredient instead of soybean oil, but that's just me.
Now--suppose I'm at a steak house and they are known for their blue cheese dressing--everyone knows that in that setting, salad dressings have no calories.
Sometimes at home I put blue cheese crumbles over lettuce. That works too (usually).