The slug in this recipe refers to the texture of the mandarin oranges. This is from the Firehouse Food: Cooking with San Francisco's Firefighters cookbook. They suggest only to use Girard's Champagne Dressing- but I'll leave that up to you.
To caramelize the almonds: Melt the butter in a small skillet over medium heat. Add the almonds and saute until golden, about 2 minutes.
Add the brown sugar and stir to combine. Spread the almonds on a baking sheet, separating them. Set aside to cool. When completely cooled, the almonds will have a hard, candied coating.
To assemble the salad: In a large bowl, toss the lettuce with the red onion, blue cheese, mandarin oranges, and dressing to taste.
Sprinkle the almonds over the salad and serve immediately.