In a bowl, mix fish sauce, sugar, and crushed garlic until the sugar dissolves. Add the wings, making sure that they are all coated in the marinade. Marinate for 4 hours, tossing them occasionally.
Heat 2 tablespoons of olive oil in a skillet over medium heat. Once hot, add in the minced garlic and cook until golden. Pay close attention as they will turn golden quickly. Drain and reserve.
In a large pan, heat frying oil to 350 degrees (the oil should be about 2 inches high). While the oil is heating, remove the wings from the marinade (reserve for later) and place them in a large bowl with the cornstarch. Thoroughly coat the wings with the cornstarch.
Fry wings in batches for about 10 minutes until golden brown. If they wings are not completely submerged, carefully turn them with tongs about halfway through cooking. Once done, remove from oil and place on a baking sheet lined with paper towels to drain.
Meanwhile, add marinade to a small sauce pan and simmer over medium-high heat until the sauce is reduced and becomes almost syrup-like - about 5 minutes.
In a bowl, toss the wings in the reduced sauce with the fried garlic and fresh mint. Serve immediately.