Place the chicken breasts (or thighs) into the bottom of your Crockpot.
In a small bowl, whisk together olive oil, lemon juice, garlic, oregano, salt, pepper, onion powder, and red pepper flakes (if using).
Pour the marinade mixture over the chicken, ensuring the chicken is well-coated.
Add the chicken broth (or water) to the Crockpot.
Cover and cook on low for 4-6 hours or on high for 2-3 hours, until the chicken is tender and fully cooked.
Once cooked, shred the chicken in the Crockpot with two forks, mixing it with the juices.
Garnish with fresh parsley and serve. Enjoy with rice, roasted vegetables, or in a wrap!