Make the candied walnuts: In a small saucepan, combine walnuts, sugar, water, and a pinch of salt. Boil, then simmer 5-7 mins until syrup thickly coats nuts. Drain and cool slightly on a plate.

Heat 1.5 inches of oil in a wok to 325°F (160°C). Fry the blanched walnuts for 2-3 mins until deep amber. Remove to a parchment-lined plate to cool and crisp. Leave oil heating.

Prepare shrimp: Pat shrimp very dry. Toss with salt and white pepper. Set up three stations: bowl with ½ cup cornstarch, bowl with beaten egg white, bowl with 1 cup cornstarch.

Coat shrimp: Dredge a few shrimp in the dry ½ cup cornstarch, dip in egg white, then coat thoroughly in the 1 cup cornstarch. Place on a wire rack.

Increase oil temp to 350°F (175°C). Fry shrimp in batches for 2-3 mins until golden and floating. Don't overcrowd. Drain on the wire rack.

Make sauce: While frying, whisk mayonnaise, sweetened condensed milk, honey, lemon juice, and vinegar in a large bowl until smooth.

Assemble: Add hot crispy shrimp and about ⅔ of the candied walnuts to the sauce. Gently fold to coat evenly.

Serve immediately on a platter, garnished with remaining walnuts, sesame seeds, and green onions.