Pat the chicken breasts dry with paper towels and season both sides evenly with kosher salt, black pepper, and garlic powder.

Heat the olive oil in a large skillet over medium-high heat. When hot and shimmering, add the chicken in a single layer and sear for 4–5 minutes per side until deeply golden.

Transfer the chicken to a plate and tent loosely with foil.

Reduce the heat to medium and add the butter to the same skillet. Once melted, stir in the minced garlic and crushed red pepper flakes. Cook for 30–60 seconds until fragrant.

Add the chopped sun-dried tomatoes and Italian seasoning, stirring to coat the tomatoes in the garlicky butter, and toast the spices for about 1 minute.

Pour in the chicken broth, scraping up any browned bits from the bottom of the pan. Bring to a gentle simmer and cook for 3–4 minutes, allowing the liquid to reduce slightly.

In a small bowl, whisk the Greek yogurt with a spoonful of warm broth from the skillet to temper it. Reduce the skillet heat to low, then slowly stir the tempered yogurt into the pan.

Add the grated Parmesan and thyme to the skillet, stirring until the cheese melts and the sauce becomes smooth and creamy. Avoid boiling the sauce once the yogurt is added.

Return the seared chicken and any accumulated juices to the skillet, turning the pieces to coat in the sauce. Simmer gently for 5–8 minutes, or until the chicken is cooked through and reaches 165°F in the thickest part.

Taste the sauce and adjust with additional salt, pepper, or red pepper flakes if needed.

Sprinkle the chicken with fresh basil or parsley, slice if desired, and serve hot with plenty of sauce spooned over the top.