How to Make It
Preheat the oven to 350°. On a large rimmed baking sheet, spread the pecans in a single layer and bake until lightly toasted, about 5 minutes. Lower the oven temperature to 275°. Transfer the pecans to a large bowl to cool.
Line the baking sheet with parchment paper. Spray the parchment with vegetable oil spray. In a medium bowl, using a Microplane, finely grate the bottom 6 inches of the lemongrass stalks. Add the egg white, lime juice, sugar, soy sauce, curry paste and salt and whisk to combine. Stir in the toasted pecans, peanuts and cashews until coated.
Spread the nuts on the parchment-lined baking sheet, leaving a small amount of the seasoning mixture in the bowl, and roast for 35 minutes, stirring once. In the same bowl, toss the coconut flakes with the residual seasoning mixture. Stir the coconut into the nuts and roast for about 30 minutes longer, stirring once or twice, until the nuts and coconut are toasted. Let cool completely.