This salad is typically made with romaine lettuce, and could be called a vegetarian orange ceasar.
It is extremely simple to make and can be put together in a few minutes, with a very high "Oooh" factor from your guests or spouse!
SO, lets first have a look at the ingredients list:
For four people:
Two nice heads of romaine lettuce,
2 medium sized oranges, peeled,
A bulb of fennel (Florence fennel, sometimes mislabeled anise in the supermarket, but actually a completely different plant!),
A large sweet red onion, or a Vidalia,
2 cups arugula,
1/2 cup Walnuts, (optional),
4 or 5 mushrooms (optional).

Dressing
1/3 cup vegenase (you can use mayo, but I choose to be completely vegan and the result is lighter),
1/2 cup orange juice,
1/4 cup Extra Virgin olive oil,
4 tablespoons balsamic vinegar,
pepper,
salt.

Step 1: Cutting and Assembly

For this example we will just make a salad for two, so the ingredients are halved.
1 Slice the fennel thinly (fennel can be tough, so this is important),
2 Cut the onion in half, and slice,
3 Chop the arugula coarsely,
4 Peel, remove the pith, and slice the orange thinly (not too thin, or it falls apart),
5 Slice the mushrooms
6 Chop the walnuts coarsely
7 Chop the lettuce,
8 mix it all together
Now make the dressing...

Step 2: The Dressing

The acidity or sweetness of a dressing is always a personal preference, so you can adjust this to taste.
The outline is 3 measures orange juice, 2 measures vegenase or mayo, 1 measure olive oil, 1/2 measure balsamic vinegar.

For our salad for two that breaks down to:
1 cup orange juice,
add
2/3 cup vegenase (or mayo)
Stir well with a fork
It may be better to add the OJ to the mayo rather than the other way around.
Slowly add 1/3 cup of extra virgin olive oil while stirring
Finish up with 2 tablespoons of balsamic vinegar.
Add pepper to taste and stir well.
Add to your salad and toss...