Pat chicken cutlets thoroughly dry with paper towels. Season both sides evenly with kosher salt, black pepper, and dried Italian herbs.

Heat 1.5 tablespoon olive oil in a heavy 12-inch cast iron skillet over medium-high heat. Once shimmering, lay chicken cutlets in a single layer and sear undisturbed for 4 to 5 minutes per side until deep golden brown and internal temperature reaches 165°F (74°C). Transfer chicken to a warm plate and tent with foil.

Reduce skillet heat to medium. Add remaining olive oil and butter. Add minced garlic and julienned sun-dried tomatoes, sautéing for 60 seconds until fragrant and aromatic.

Pour in the chicken bone broth and lemon juice, using a flat wooden spoon to firmly scrape up all the caramelized golden browned fond from the bottom of the pan. Let liquid simmer for 2 minutes until reduced by half.

Pour in heavy whipping cream and bring to a gentle simmer. Reduce heat to medium-low and whisk in grated parmesan cheese until completely smooth and melted.

Add baby spinach by the handful, gently folding it into the warm cream sauce until wilted (about 90 seconds). Season sauce with additional black pepper to taste.

Nestle seared chicken cutlets along with their resting juices back into the bubbling sauce. Spoon velvety garlic sauce over the chicken and simmer for 1 minute to reheat. Garnish with fresh oregano and serve immediately.