This isn't Mom's bacon-dressed spinach salad.
The bacon has been replaced with a leaner, lighter and sweeter cured-pork product: prosciutto from Parma, Italy.
Toasted walnuts add crunch, and the combination picks up zing from a vinegary mix of sauteed onions and apples softened by a little maple syrup. I prefer just a hint of maple, but if you'd like a stronger maple taste, increase the amount of maple syrup you use.
Take note: The dressing can be made up to a day in advance. Bring it to room temperature before using. You might need to mix in a tablespoon of oil or water, your choice, to loosen it up.