Heat a large skillet over medium-high heat. Add a drizzle of oil and cook the chicken pieces for 5–7 minutes, stirring occasionally, until golden brown and fully cooked.
In a small bowl, mix the orange marmalade and soy sauce. For a thicker sauce, stir in a cornstarch slurry (1 tablespoon cornstarch + 2 tablespoons water).
Reduce heat to low and pour the orange sauce over the cooked chicken. Stir well, making sure each piece is coated. Let it simmer for 3–5 minutes until the sauce thickens and caramelizes slightly.
Remove from heat and serve immediately over steamed rice or with stir-fried vegetables. For extra crunch, sprinkle sesame seeds or chopped green onions on top.