Preheat oven to 500°F. Place a rimmed baking sheet in oven (do not remove pan while oven preheats).
Combine potatoes, tofu, 2 tablespoons oil, curry powder, and 1 teaspoon salt in a bowl; toss to coat. Carefully remove pan from oven. Coat pan with cooking spray. Arrange potato mixture in a single layer on pan; bake at 500°F for 10 minutes, stirring once after 5 minutes. Add remaining 1 tablespoon oil and cauliflower to pan; toss gently to combine. Bake at 500°F until potatoes are tender, 10 to 12 minutes. Remove pan from oven.
Whisk together remaining 1/4 teaspoon salt, yogurt, and juice in a small bowl. Drizzle yogurt mixture evenly over tofu mixture. Sprinkle with mint, cashews, and pomegranate arils.