01 - Season the chicken breasts or thighs generously with salt and freshly ground black pepper on both sides, ensuring even coverage for maximum flavor penetration.
02 - Heat olive oil in a large skillet over medium-high heat until shimmering. Add chicken and sear for 2-3 minutes per side until golden brown. Remove from skillet and set aside on a plate.
03 - In the same skillet, add diced white onion and jalapeño. Sauté for 2 minutes until softened and translucent. Add minced garlic and cook for 30 seconds until fragrant, being careful not to burn.
04 - Stir in salsa verde, ground cumin, dried oregano, and fresh lime juice. Bring the mixture to a gentle simmer, stirring occasionally to combine flavors.
05 - Return seared chicken to the skillet. Reduce heat to low, cover with lid, and simmer for 15-18 minutes until chicken is cooked through and tender, reaching an internal temperature of 165°F.
06 - Remove chicken from skillet and shred using two forks. Return shredded chicken to the sauce; stir well to coat evenly and simmer for 2 additional minutes to allow flavors to meld.
07 - Serve chicken in warm corn tortillas. Top generously with fresh cilantro, diced red onion, avocado slices, and a squeeze of fresh lime. Add additional salsa verde if desired.