Preheat oven to 450°F. Stir oil and curry powder together in a medium bowl. Add cauliflower; toss until well coated. Arrange in an even layer on a large rimmed baking sheet. Roast until browned, about 15 minutes. Let cool completely, about 10 minutes.
Meanwhile, whisk yogurt, celery, cashews, mayonnaise, cilantro, parsley, maple syrup and mustard together in a medium bowl until combined and creamy. Gently stir in pomegranate arils.
Coarsely chop the roasted cauliflower into bite-size pieces; add to yogurt mixture. Stir to coat. Using a serrated knife, cut across top of baguette, cutting to, but not through, the other side. Slice the baguette into 4 equal portions. Fill each baguette portion with ½ cup of the cauliflower mixture.
