How to Make It
Line a small baking sheet with parchment paper. In a small saucepan, combine the granulated sugar and 1/4 cup of water. Boil over moderately high heat, swirling the pan until a rich brown caramel forms, 4 minutes. Stir in the cashews until coated. Quickly spread the nuts on the baking sheet, keeping them separate. Let cool. Break off any large pieces of caramel and reserve for a snack.
In a small saucepan, combine the vegetable oil, garlic, scallion and ginger. Cover and cook over low heat for 1 minute. Remove from the heat and let stand, covered, for 10 minutes. Strain the oil through a coarse strainer into a medium skillet, pressing on the solids. Add the soy sauce, brown sugar and 1/4 cup of water and bring to a simmer over moderate heat. Whisk in the cornstarch mixture and simmer over low heat, whisking, until thickened, about 30 seconds. Remove from the heat, add 1 tablespoon of the lemon juice and lightly season the sauce with salt.
In a medium saucepan, melt the butter in the 1/4 cup of olive oil. Season the chicken with salt and pepper and add to the saucepan. Cook over moderate heat, turning, until white throughout, about 5 minutes.
In a small bowl, combine the onion and garlic powders, celery seeds and 1/2 teaspoon of salt. In another small bowl, toss the sliced celery and leaves with the remaining 1/2 teaspoon of lemon juice and a small drizzle of olive oil and season with salt and pepper.
Transfer the chicken to shallow bowls, spooning the sauce over the chicken. Top with the candied cashews and season with the celery salt. Scatter the celery salad on top and serve with rice. Alternatively, arrange the chicken on cocktail forks and season with the celery salt. Serve with the sauce, candied cashews and celery salad.
The candied cashews can be stored in an airtight container at room temperature for 1 day. Reheat briefly in a 350° oven if they are sticky. The sauce can be refrigerated overnight; reheat gently.