Place the chicken breasts, salt, peppercorns, onion, whole garlic cloves, bay leaves, and water in a large pot.
2. Step
Cover the pot and bring to a simmer over medium heat.
3. Step
Once the water is simmering, cook for 10 minutes, until the chicken registers 165°F (74°C) when pierced with an instant-read thermometer.
4. Step
Transfer the chicken to a cutting board and reserve at least ¾ cup (180 ml) of the cooking liquid to use as broth. Using 2 forks, pull the chicken apart until shredded.
5. Step
In a large nonstick pan, heat the oil over medium heat until shimmering.
6. Step
Add the minced garlic, cumin, paprika, chili powder, and oregano. Sauté until the oil is bubbling and very fragrant, about 2 minutes.
7. Step
Add the chicken broth and stir until the liquid has reduced and thickened slightly, about 7 minutes.
8. Step
Add the shredded chicken and mix until everything is well incorporated.
9. Step
Remove the pan from the heat and let the chicken cool for 5 minutes before spooning into the lettuce leaves.
