In a medium bowl, toss the chicken with the chili powder and half of the garlic.
Wrap the tortillas in a sheet of foil, place in the oven and turn to 350 degrees . Let them warm while you cook the chicken and vegetables.
Heat a 12-inch cast-iron skillet over medium-high heat until hot. Add 1 1/2 tbsp. EVOO and the chicken; season with salt and pepper. Cook, stirring, until the chicken is no longer pink, about 5 minutes. Using a slotted spoon, transfer the chicken to a bowl.
Add the remaining 1 1/2 tbsp. EVOO and garlic, the frying peppers and onion to the skillet and cook over medium heat, stirring, until beginning to char, about 3 minutes. Stir in the mushrooms and cook, stirring occasionally, until the onion is crisp-tender, about 5 minutes.
Return the chicken to the pan and cook, stirring, until the vegetables are tender and the chicken is hot, about 2 minutes. Season with salt and pepper to taste. Serve the chicken-vegetable mixture with the warmed tortillas and yogurt.