Put new potatoes in a large saucepan and add enough water to cover them. Add 1 teaspoon of the salt and bring to a boil. Let the potatoes boil until they are fork tender, about 10 minutes. Drain. Quarter the potatoes and put them in salad bowl. Set aside.

Cook the bacon in a large sauté pan over medium-high heat until slightly crisp, about 10 minutes.  Remove and save for another use all but 2 tablespoons of the bacon fat. Add the onions, another teaspoon of salt, and 1/4 teaspoon of the pepper to the pan. Cook, stirring until the onions are wilted and lightly golden, about 10 minutes, stirring often.  Add the walnuts and continue to cook 5 minutes longer.

Remove from the heat. Add the garlic and stir the mixture for about 30 seconds. Add the vinegar and the oil and mix well.

Add 1/2 cup of the dressing mixture and 1/2 teaspoon of the salt to the potatoes and gently toss to coat evenly. Transfer the potatoes to another bowl and set aside. To the salad bowl, add the spinach, the remaining 1 1/2 cups of the dressing, and the remaining 1/2 teaspoon salt and pepper. Toss to coat the leaves evenly.

Divide the spinach into six equal portions and mound in the center of each plate. Sprinkle each with equal portions of the cheese. Arrange potato quarters around each mound. Serve immediately.  Alternatively, combine the potatoes, spinach, bacon vinaigrette, and cheese together and serve family style from a large bowl.