My grandfather was right. Secret techniques that chefs hide from you!

Ingredients:
1 piece chicken
Onion 1 piece
Garlic 2 cloves
Tomatoes 2 pcs
Vegetable oil 500ml
Potatoes 1.5kg
Butter 140g
Bay leaf 2 pcs
Salt 1.5 teaspoons
Pepper, coriander, cumin 1 teaspoon each
For the salad
Cabbage 1/2 pcs
1 piece carrot
Garlic 2 cloves
Hot pepper 1 pc
Vegetable oil 20ml
Soy sauce 1 tablespoon
Oyster sauce 2 tablespoons