Heat a 12-inch nonstick skillet over MEDIUM heat, spray with nonstick cooking spray.
When hot, add the ground turkey and onion and cook, breaking up the meat with a wooden spoon, 5 minutes. Drain any excess grease and return the skillet to the heat.
Add the tomato paste, and cook, stirring it into the meat for a minute or two, until well combined. Add the salt, chili powder, garlic powder, cumin, oregano, and red pepper flakes. Cook, stirring, for one minute to toast the spices then add the water. Reduce the heat to LOW and cook, stirring occasionally, for 2 to 3 minutes more. Remove the skillet from the heat.
Preheat oven to 400 degrees F and line a large baking sheet with parchment paper or foil.
Arrange the mini peppers, cut side up, on the prepared baking sheet. Divide the ground turkey filling between the peppers and top with the shredded cheese.
Bake for 8 to 10 minutes, or until the peppers are fork tender and the cheese is melted.
Remove from the oven and drizzle a little of the thinned sour cream over each pepper and garnish with cilantro leaves and pickled jalapenos. Serve immediately.