Grown up Green Salad

1 head iceberg lettuce
1 package spring salad mix
1/2 cup bacon bits or diced cooked bacon
Mix above together and pour dressing over mixture right before serving
Dressing:
1 pkg mushrooms sliced
1/4 cup diced purple onion
1 cup vegetable oil
1/2 cup vinegar
1/2 cup sugar
2 TBSP yellow prepared mustard
4TBSP poppy seeds (can leave out and is yummy also)