Clean and devein the prawns, ensuring they are patted dry with a paper towel.

In a medium bowl, mix together cornstarch, salt, black pepper, and chili flakes.

Toss the cleaned prawns in the cornstarch mixture until they are completely coated.

In a deep pan, heat enough oil over medium-high heat until it shimmers.

Carefully add the coated prawns in small batches, frying for about 2-3 minutes or until they achieve a golden brown color.

Once fried, remove the prawns with a slotted spoon and place them on a plate lined with paper towels.

In the same pan, sauté the minced garlic and sliced green onions for about a minute until fragrant, then toss them with the fried prawns.

Arrange the hot prawns on a serving platter and sprinkle additional chili flakes or sesame seeds on top if desired.