I had that too....it was delicious....think the dressing was a basic poppy seed vinaigrette....
Don't know what book it was in...or magazine.
Linda C

Years ago I made a salad similar to the one at the link below. Don't remember putting chile powder in the dressing altho I served it with Mexican food.

Also this recipe from Sunset sounds good:

Orange-Red Onion Salad - 8 servings

1 red onion (3/4 lb.), cut in thin rings
4 large oranges (2 3/4 lb. total)
3 quarts inner leaves (8 in. or smaller) from 2 heads romaine lettuce (save large leaves for other uses)
4 large radishes, finely shredded
Whole radishes and orange slices

1/4 cup extra-virgin olive oil
3 tablespoons red wine vinegar
Salt and pepper

1. In a large bowl, cover onion with boiling water; let stand 15 minutes. Drain, rinse with cold water, then pat dry. Chill airtight until very cold, about 2 hours.

2. With a sharp knife, cut peel and white membrane from outside of oranges. Cut between inner membranes to free segments; discard membranes and peel.

3. Place romaine in a bowl; add onion and orange segments on top; scatter shredded radishes over all. Garnish with whole radishes and orange slices. Serve, or chill airtight up to 4 hours.

4. In a tightly capped jar, shake oil and vinegar to blend; season with salt and pepper. Shake again before serving; pour over salad.

Here is a link that might be useful: http://www.cooksrecipes.com/salad/orange_&_onion_salad_recipe.html

This recipe is from food network- it is FENELL and orange
really really good/ I added some red onion

Orange Fennel Salad 2007, Ina Garten, All Rights Reserved
See this recipe on air Friday Mar. 21 at 5:00 PM ET/PT.

2 pounds fennel bulbs
3 to 4 oranges
1/4 cup good olive oil
2 lemons, juiced
Kosher salt
1/4 teaspoon freshly ground black pepper
2 ounces arugula

Cut the fronds from the fennel bulbs and reserve some of the feathery leaves for later. Cut each fennel bulb in half and remove the cores with a sharp knife.
Fit a food processor with the thinnest slicing blade. Cut the fennel bulbs into wedges and place horizontally into the feed tube. Process in batches. Peel each orange, remove the pith with a knife, and slice. Set aside.
For the dressing
Whisk together the oil, juice, 1 teaspoon salt and the pepper in a small bowl. Place the fennel slices, oranges slices and arugula in a large bowl. Pour the dressing over the salad and toss together. Sprinkle with salt and add some fennel fronds for decoration.

It really is great !