Prepare the frozen crispy chicken strips according to package directions (air-fryer or oven). Let them cool until warm, then cut into bite-sized pieces and place in a large bowl.
In a medium pot over medium-high heat, add 2 tablespoons toasted sesame oil. When the oil shimmers, add the minced garlic, ginger paste, and red pepper flakes and cook, stirring constantly, for about 30 seconds.
Add the light brown sugar and granulated sugar to the pot and stir to moisten the sugar. Add 1/2 cup fresh orange juice (from 1–2 oranges) and stir until the sugar dissolves.
Stir in the white vinegar and soy sauce, then bring the mixture to a gentle simmer.
In a small bowl, whisk the cornstarch with 1/4 cup water until completely smooth. Pour the cornstarch slurry into the simmering sauce and stir continuously until the sauce thickens to a syrupy consistency.
Taste the sauce and adjust seasoning if desired (add more red pepper flakes for heat or a pinch of salt if needed).
Pour the desired amount of sauce over the cut-up chicken pieces in the large bowl. Drizzle the remaining 2 teaspoons toasted sesame oil over the coated chicken and gently toss to combine.
Serve immediately over cooked rice if using, and garnish as desired.