Preheat Oven: Preheat your oven to 425°F (220°C).

Peel and Cube Potatoes: Wash and peel the russet potatoes. Cut them into even-sized cubes, ensuring they are of uniform thickness. This helps in achieving consistent crispiness.

Rinse and Dry: Rinse the cubed potatoes under cold water to remove excess starch. Pat them dry thoroughly with a clean kitchen towel.

Coat with Cornstarch: In a large bowl, toss the dried potato cubes with cornstarch until each piece is evenly coated. This helps create a crispy exterior.

Add Oil and Salt: Drizzle the vegetable oil over the cornstarch-coated potato cubes. Sprinkle salt evenly. Toss the cubes again to ensure they are well coated with oil and seasoning.

Arrange on Baking Sheet: Line a baking sheet with parchment paper. Arrange the coated potato cubes in a single layer on the baking sheet. Avoid overcrowding to ensure even baking and crispiness.

Bake in the Oven: Place the baking sheet in the preheated oven. Bake for about 25-30 minutes or until the potato cubes are golden brown and crispy. Remember to flip the cubes halfway through the baking time for even crispiness.

Check for Doneness: Pierce a cube with a fork to check for doneness. They should be tender on the inside while maintaining a crispy exterior.

Serve Immediately: Once the crispy potato cubes are done baking, remove them from the oven. Serve immediately while they are hot and at their crispiest.

Enjoy: These crispy potato cubes make a fantastic side dish or snack. Serve them with your favorite dipping sauce or enjoy them on their own for a delightful and crunchy treat!