Fresh Broccoli Mandarin Salad

For my dinner tonight I had a bowl of potato soup, a dinner roll and this salad. I had seen this recipe in a small booklet I had purchased not too long ago and decided to try it. (yes, still buying recipe books!) It was very good. I didn't put in the mushrooms as I really don't like them to eat, although I do like to add them to baked dishes such as chicken beef, etc. I just pick them out! LOL! Fresh Broccoli Mandarin Salad.........

1 egg plus 1 egg yolk, lightly beaten
1/2 cup granulated sugar
1 1/2 teaspoons cornstarch
1 teaspoon dry mustard
1/4 cup tarragon wine vinegar
1/4 cup water
1/2 cup mayonnaise
3 tablespoons butter, softened
4 cups fresh broccoli flowerets
2 cups sliced fresh mushrooms
1 can (11ozs.) mandarin oranges, drained
1/2 cup raisens
1/2 cup slivered almonds, toasted
1/2 large red onion, sliced
6 slices bacon, cooked and crumbled

In the top of a double boiler, whisk together egg, egg yolk, sugar, cornstarch, and dry mustard. Combine vinegar and water. Slowly pour into egg mixture, whisking constantly. Place over simmering water and cook, stirring constantly, until mixture thickens. Remove from heat; stir in mayonnaise and butter. Chill.
To serve, toss dressing with salad ingredients.