Prepare the Cauliflower: Preheat your oven to 425°F (220°C) or prepare an air fryer. Pat the cauliflower florets dry, ensuring no excess moisture. Toss the florets in cornstarch until evenly coated. This will create a crispy exterior once cooked.

Cook the Cauliflower: Place the coated cauliflower florets on a baking sheet lined with parchment paper. Bake for 20–25 minutes, flipping halfway, until golden and crispy. Arrange the florets in a single layer in the air fryer basket. Air fry at 400°F (200°C) for 15 minutes, shaking the basket halfway through.

Prepare the Sauce: In a small bowl, whisk together water and 1 teaspoon of cornstarch to create a slurry. Set aside. In a medium saucepan over medium heat, combine soy sauce, ketchup, brown sugar, garlic, ginger, black pepper, and chili flakes (if using). Bring the mixture to a simmer, then stir in the cornstarch slurry. Cook for 1–2 minutes, stirring constantly, until the sauce thickens.

Combine the Cauliflower and Sauce: Remove the cauliflower from the oven or air fryer and transfer it to a large mixing bowl. Pour the sauce over the cauliflower and gently toss to coat evenly.

Add Cashews: Stir in the roasted cashews for a crunchy texture and nutty flavor. Mix well.

Serve and Enjoy: Serve the Cashew Cauliflower immediately as a standalone dish or over steamed rice or noodles for a complete meal. Garnish with green onions or sesame seeds, if desired.