Whisk together vinegar, honey, Dijon, and orange juice in a small bowl for the vinaigrette. Drizzle in oil, whisk until emulsified. Season with salt & pepper.
Marinate orange and onion slices in vinaigrette in a shallow dish (such as a pie plate) for 10 minutes
Toast almonds in butter in a small non-stick skillet over medium heat. When barely golden brown add sugar, salt & cayenne. Continue cooking, stirring, constantly, until almonds are browned and coated with sugar. Transfer nuts to a plate to cool.
To assemble, arrange greens on a platter; top with orange and onion slices and desired amount of vinaigrette. Sprinkle with scallions (or chives) and candies almonds.