What You Need
To make the sauce, combine the boiled tomatoes, onion, canned chipotles, chicken broth, halved garlic cloves, and salt in a blender. Blend until smooth. Set aside.
To make the tinga, heat the olive oil on a 30 cm HexClad Hybrid Pan over high heat. Add the onion and minced garlic and sauté for 5 minutes. Add the chicken and stir to combine. Strain the tomato sauce through a fine-mesh strainer into the pan and stir to combine. Bring to a boil over high heat, lower the heat to medium-low, and simmer to reduce slightly, about 20 minutes.
Season the tinga with salt and black pepper to taste.
To serve, place a tostada on a plate. Spread with about 45 milliliters of refried beans, then top with approximately 80 to 120 milliliters of the tinga. Top with shredded lettuce, then avocado slices, crumbled cheese, and crema and hot sauce, if desired. Serve with lime wedges.