In a large skillet, heat the vegetable oil over medium heat. Add the chopped onion and sauté until it turns translucent, about 5 minutes. Then, stir in the chopped jalapeño and minced garlic, cooking for an additional 2 minutes until fragrant.
Add the boneless skinless chicken thighs to the skillet. Cook for about 5 minutes on each side until they are browned. This step locks in flavor and gives the chicken a nice texture.
Pour in the fire roasted diced tomatoes, chipotle peppers in adobo sauce, and dried oregano. Stir well to combine all the ingredients. Bring the mixture to a boil, then reduce heat to low, cover, and let it simmer for 25-30 minutes. This allows the chicken to become tender and soak up all the flavors.
Once the chicken is cooked through, remove it from the skillet and place it on a cutting board. Use two forks to shred the chicken into bite-sized pieces. Return the shredded chicken to the skillet and mix it back into the sauce. Let it simmer for an additional 5-10 minutes to absorb more flavor.
While the chicken is simmering, warm your corn tortillas. You can do this in a dry skillet over medium heat for about 30 seconds on each side or wrap them in foil and heat them in the oven.
To assemble your Saucy Chicken Tinga Tacos, take a warm tortilla and fill it with the shredded chicken mixture. Top with crumbled cotija cheese, thinly sliced red onion, and fresh cilantro. Serve with lime wedges on the side for an extra burst of flavor.
