First Step: Prepare Aromatics
Heat 1 tablespoon of olive oil in a large skillet over medium heat. Add 1 cup roughly chopped sweet onion and sauté for about 4 minutes until tender. Stir in 2 cloves minced garlic and cook for an additional 30 seconds to release their aroma.

Second Step: Build the Sauce
Add 1 to 2 chopped chipotle peppers in adobo sauce (adjust to your preferred level of heat), 1 teaspoon dried oregano, and ½ teaspoon ground cumin. Toast the spices for about 1 minute, stirring frequently to awaken their flavors.

Third Step: Simmer the Tomato Base
Pour in ¾ cup canned crushed fire-roasted tomatoes along with ¼ cup chicken stock (or ⅓ cup water if needed). Add ½ teaspoon kosher salt. Bring the mixture to a simmer and cook for 7 minutes, allowing the flavors to develop and intensify.

Fourth Step: Blend the Sauce
Transfer the tomato mixture to a blender and puree until smooth. Return the sauce to the skillet on low heat. This step creates a consistent, velvety base for the chicken tinga.

Fifth Step: Add and Cook Chicken
Stir in 3 cups shredded cooked chicken, ensuring it is well coated with the sauce. Simmer for 5 minutes so the flavors meld into the chicken. Taste and adjust salt or chipotle peppers as needed to achieve your preferred heat level.

Sixth Step: Warm the Tortillas
Lightly char 10 (6-inch) corn tortillas over an open flame for authentic smokiness or heat them in a dry skillet or microwave wrapped in a damp towel to keep them pliable. For a crispier taco, rub tortillas with olive oil, fill with cheese and chicken tinga, and bake at 425°F for 5-8 minutes per side until cheese melts and tortillas crisp.

Final Step: Assemble and Serve
Mash or slice 2 ripe avocados; optional mixing with lime juice and garlic salt creates extra flavor. Spread avocado on each tortilla, top with chicken tinga, and garnish with ¼ cup chopped fresh cilantro, ½ cup diced red or pickled onions, and ¼ cup crumbled cotija or shredded cheese. Serve with lime wedges and optional toppings like shredded lettuce, pickled jalapeños, or honey for added texture and flavor.