Shred the chicken and set aside.
10 ounces cooked chicken (about 2 cups once is shredded)
In a small cup add the chipotles, ketchup, soy sauce, vinegar, chili powder. Mix to combine and set aside.
2 tablespoons chipotle in adobo sauce, ¾ cup ketchup, 2 tablespoons soy sauce, 2 tablespoons apple cider vinegar, ½ teaspoon chili powder (use 1 for more spicy)
In a large skillet, add heat the oil over medium high heat. Add the onion and saute until it starts to become translucent.
1 teaspoon olive oil, ½ medium white or yellow onion
Add the chicken and chipotle sauce and stir to combine. Cover pot and simmer over medium-low heat for about 8 minutes, or until sauce is syrupy. Make sure to stir often to prevent the bottom from burning and sticking.
Meanwhile, reheat the refried beans and keep them warm until ready to assemble the tostadas.
1 cup refried beans
Top each tostada with a thin layer of refried beans, then ¼ cup of the chicken mixture.
Garnish each tostada with shredded lettuce, chopped tomatoes and avocados. Finish with a squeeze of fresh lime juice and your favorite hot sauce.