Two Cheese Salad

1 head green leaf lettuce, chopped
1 small bunch Romaine lettuce, chopped
3/4 pound Swiss cheese, grated
1 pound cottage cheese
3/4 pound fresh mushrooms, sliced
1/2 pound cooked bacon, crumbled
2 T purple onion, diced

Dressing:
1/4 cup white vinegar
1/4 cup oil
2 T sugar
1 T poppy seeds
1 T dried minced onion
1 t salt
1 t dry mustard