Chicken Tinga Tacos

• 1 tablespoon olive oil
• 1 cup roughly chopped sweet onion
• 2 cloves garlic, minced
• 1-2 chipotle peppers in adobo sauce, chopped
• 1 teaspoon dried oregano
• 1⁄2 teaspoon ground cumin
• 3⁄4 cup canned crushed fire-roasted tomatoes
• 1⁄4 cup chicken stock
• 1⁄2 teaspoon kosher salt
• 3 cups shredded cooked chicken 

For Serving:

• 10 (6-inch) corn tortillas
• 2 ripe avocados, sliced
• 1/4 cup chopped fresh cilantro
• 1/2 cup diced red onion
• crumbled cotija (Or feta or any cheese you want really!)
• 1 lime, cut into wedges

1. Sauce: Heat a large skillet over medium. Once warm, add the oil and onion. Sauté for 4 minutes or until tender, stirring occasionally. Add in the garlic and cook for 30 seconds more. Stir in the chipotles, oregano, and cumin, and toast for 1 minute. Add in the tomatoes, stock, and salt. Bring to a simmer, and cook for 7 minutes.
2. Blend: Place the tomato mixture in a high-powered or regular blender, and blend until smooth.
3. Chicken: Return the blended sauce to the pan over low heat. Add the chicken, and cook for 5 minutes. Taste and add more salt if necessary.
4. Serving: Prepare the garnishes. To assemble, top the tortillas with the chicken and garnish with the avocado slices, cilantro, red onion, and cotija. Serve with a lime wedge for squeezing.