In a small bowl, whisk together vinegar, honey, mustard, garam masala and garlic until well combines. Whisking constantly, slowly drizzle in oil until emulsified in the vinegar mixture. Set aside.
Combine the carrots, cauliflower, apple, onion and parsley in a large mixing bowl. Pour over dressing and stir until well combined. Cover and refrigerate for at least 2 hours or overnight to allow flavours to meld.