Prep the chicken: Pat chicken dry. Slice larger breasts horizontally into cutlets for even cooking.
Season both sides with 1/2 teaspoon salt, pepper, Italian seasoning, and smoked paprika.
Sear: Heat olive oil in a large skillet over medium-high. Add chicken and cook 3–4 minutes per side until golden and just cooked through (internal temp 165°F). Transfer to a plate and tent loosely with foil.
Sauté aromatics: Reduce heat to medium.
Add garlic and cook 30 seconds until fragrant, scraping up browned bits.
Build the sauce: Stir in chicken broth and milk. Simmer 2–3 minutes to reduce slightly.
Add flavor: Whisk in Parmesan until melted. Remove pan from heat.
In a small bowl, whisk Greek yogurt with a few tablespoons of the hot sauce to temper. Then stir the tempered yogurt into the skillet. Return to low heat and warm gently—do not boil.
Veggies: Add tomatoes and simmer 1 minute.
Stir in spinach until just wilted.
Finish: Stir in lemon juice, remaining 1/2 teaspoon salt (adjust to taste), basil, and red pepper flakes if using.
Combine: Nestle chicken back into the sauce and spoon sauce over the top. Warm 1–2 minutes. Serve immediately.