Pound chicken breasts to uniform ½-inch thickness using a meat mallet. This ensures even cooking throughout—critical for tender, juicy results. Season both sides generously with salt and pepper.

Combine flour with Italian seasoning in a shallow bowl. Dredge each chicken breast thoroughly, shaking off excess flour to prevent clumpy coating. Pat gently so the flour adheres evenly across the surface.

Heat olive oil in a large skillet over medium-high heat until shimmering. Carefully place chicken breasts in the pan and cook for 5-6 minutes per side until golden brown. Transfer to a clean plate—the chicken doesn't need to be fully cooked through yet.

Reduce heat to medium and add butter to the same skillet. Sauté minced garlic for exactly 60 seconds until fragrant. Pour in chicken broth and heavy cream simultaneously, stirring constantly to combine smoothly and prevent lumps.

Return chicken to the skillet and nestle it into the creamy sauce. Simmer gently for 4-5 minutes until the internal temperature reaches 165°F when measured with a meat thermometer inserted at the thickest point. This final step cooks the creamy parmesan chicken elegant through while infusing it with sauce flavors.

Sprinkle grated Parmesan cheese directly over the chicken and sauce, stirring gently until completely melted and smooth. Remove from heat and fold in fresh spinach until wilted, about 1-2 minutes of gentle stirring.

Squeeze fresh lemon juice over the entire dish and taste for seasoning. Add red pepper flakes for subtle heat if desired. Serve immediately over cooked pasta while the sauce remains silky and warm.