For the taco seasoning: Mix together the chili powders, coriander, cumin, garlic powder, oregano, paprika, celery salt, kosher salt and cayenne in a small bowl. Set aside 1 tablespoon plus 2 teaspoons, and reserve the rest in an airtight container at room temperature for another use.
For the tostadas: Heat the oil in a large skillet over medium-high heat. Preheat the oven to 350 degrees F.Place chips in on a broiler-proof baking sheet set aside. Brown the turkey in the skillet, breaking it up with a fork, until the meat is no longer pink, 5 to 7 minutes. Add 1 tablespoon of the taco seasoning, salsa and some salt and black pepper. Continue cooking, stirring occasionally, until most of the liquid has evaporated.
Spread turkey mixture across all the chips and top with the cheese. Broil long enough to melt cheese and heat the chips, and then let cool. Place the yogurt, cilantro, avocado, lime juice and zest and remaining taco seasoning in a food processor and pulse until well combined. Serve the mini tostadas topped with the avocado cream. Garnish with cilantro.