Wash the bean sprouts thoroughly and drain the water.
Cut the smoked duck into bite-sized pieces.
Prepare the mala sauce in advance.
Place the smoked duck in a pan and render the fat over medium heat.
Once the duck is cooked, add the bean sprouts and stir-fry.
Add the mala sauce and stir-fry quickly over high heat.
Season with salt and serve immediately on a plate.