Boil your chicken breast fillet in a pan of water along with the bayleaf, leek, whole peppercorns, and salt until cooked through. This takes about 20 to 30 minutes.
While that is cooking, mince the white onion and garlic separately. Slice your chili pepper if using.
Remove cooked chicken from pan and shred. Save the water it boiled in to another container. That's delicious liquid gold.
In the same pan you used (no need to wash), add the olive oil and heat to medium.
Add your minced onions until translucent, then add the minced garlic and cook until fragrant, stirring occasionally. Add in your chili peppers if using until cooked through.
Add your shredded chicken to the pan, followed by the soy sauce and the turmeric powder. Stir until the color from the soy sauce and turmeric is spread even. Add more soy sauce if needed.
(Optional) You can add a tablespoon at a time of the liquid the chicken boiled in so it doesn't dry out and it also adds some flavor.
Once the flavor is to your liking, adjust the heat to high to toast the chicken. Spread the chicken on the pan to touch more surface area. Leave it alone for about 3 to 4 minutes, stir, and repeat, so more chicken gets a bit more toasted. This is for additional flavor and texture.
Serve over white rice.