How to Make It
In a large bowl, toss the cabbage-and-carrot coleslaw, red bell pepper, scallions, and grape tomatoes together. Set aside.
Combine the horseradish and next four ingredients (through salt) in a small jar and shake until blended. Remove the lid and add the canola oil. Shake again. Or whisk the ingredients together in a small bowl.
Pour dressing over the salad and toss to coat vegetables. Serve immediately, or refrigerate until ready to serve.