Place the chicken in a bag, add one tablespoon of corn flour, a quarter of a teaspoon of salt and the ground pepper and seal the bag.
Shake it well so that the chicken can be coated evenly.
Heat up two tablespoons of oil in a pan, add the chicken and fry until brown and cooked through.
Peel and grate the garlic cloves and ginger, chop the spring onions and add them to a wok together with half a teaspoon of oil.
Stir for 30 seconds, then add peppers and onion chopped roughly.
Stir well for about 5 minutes, so that the vegetables can soften. A high heat is recommended when stir frying.
Season with salt to taste.
In a separate pan, combine the ketchup, soy sauces, vinegar, sugar and sesame oil.
Mix one tablespoon of corn flour with two tablespoons of cold water, then add the mixture to the pan.
Stir gently on a medium heat until the sauce thickens.
Pour it over the vegetables, add the cooked chicken and mix well.
Serve hot!