To a large pot of boiling water, add the asparagus. Blanch for 1 minute; drain, and plunge asparagus into a bowl of cold water. Drain again and dry.
In a large bowl, combine the asparagus, endive, oranges, and red onion.
Whisk together the raspberry vinegar, canola oil, orange juice, sugar and salt and pepper. Add dressing to the asparagus endive mixture; toss well and serve.
