Cut the chicken into strips. Finely dice the onion and mince the garlic.
Heat the oil in a large pan over medium-high heat. Fry the chicken strips for 3-4 minutes until golden.
Add the onion and garlic, fry for 2 minutes until softened.
Add the corn, mushroom slices, and pineapple pieces with their liquid. Bring to a boil.
Reduce heat to medium and simmer for 10 minutes. Season with curry powder, salt, and pepper to taste.
For a creamier sauce (optional): mix cornstarch with cold milk to a smooth paste, stir into the simmering sauce, and remove from heat immediately to prevent over-thickening.
Ensure the chicken has reached 74°C (165°F) internal temperature.