Place sugar, vinegar, dry mustard, salt, and onion in blender. Turn on blender and through opening in blender lid slowly add 1 cup canola while blending. Blend until onion is all chopped into dressing and is well blended with the oil. Add poppyseeds and pulse just to mix them in.
Combine salad ingredients and pour desired amount of salad dressing over. Toss to coat. Serves 8.