Swiss Mushroom Spinach Salad

I remember this from childhood.  It's a delicious high calorie salad.  Nice with a ham.

2 bunches Spinach - washed and de-stemmed
1/2 lb fresh mushrooms, sliced
1/2 lb swiss cheese
1/3 cup cottage cheese
5 strips bacon - cooked and crumbled
1 red onion, diced (you can soak prior to take the edge off the raw onion)

Hard Boiled Egg (optional)

Dressing (can be made a day prior)
1/2 cup sugar
1 cup Olive oil
1/2 cup Red Cider vinegar
1 T Poppy Seed
1 T minced Red Onion
1 tsp salt
1/2 t. Dry Mustard

Blend all of the dressing ingredients together in a blender. Marinate mushrooms in dressing for 15 minutes. Combine all of the ingredients for the salad and toss with dressing just before serving to prevent wilting.