Grate the fresh ginger and press the garlic cloves through a garlic press. Mix both with the soy sauce.
Wash and pat dry the chicken breast, remove any tendons, and cut into thin strips. Mix with the ginger-garlic-soy sauce, cover, and refrigerate for 30 minutes.
While the chicken marinates, wash, core, and finely dice the red pepper.
Peel the mango and cut the flesh into lozenges.
Heat the peanut or rapeseed oil over medium-high heat. Fry the curry paste for 1 minute. Add the marinated chicken strips and fry over medium-high heat for 2 minutes until starting to brown. Add the diced pepper, reduce heat to medium, and cook for 3-4 minutes, stirring occasionally, until the chicken reaches 74°C / 165°F internal temperature and the peppers are tender-crisp.
Pour the water (about 50 ml) into the pan to deglaze and stir in the peanut butter until fully combined.
Add the mango to the pan and gently heat for 1-2 minutes, being careful not to overheat.