Bring a large pot of salted water to boil for pasta. Cook according to package directions until al dente, reserving 1 cup pasta water before draining.

While water heats, pound chicken breasts to even 3/4-inch thickness. Season both sides with salt, pepper, and Italian seasoning.

Heat olive oil in a large skillet over medium-high heat. Add seasoned chicken and cook for 6-7 minutes per side until golden brown and cooked through.

Remove chicken to a plate and let rest for 5 minutes, then slice into bite-sized strips.

In the same skillet, reduce heat to medium and add butter. Once melted, add minced garlic and diced shallot.

Sauté aromatics for 1-2 minutes until fragrant but not browned.

Add white wine if using, scraping up any browned bits from the bottom of the pan. Cook for 1 minute to reduce slightly.

Slowly pour in heavy cream, stirring constantly. Bring to a gentle simmer.

Add grated Parmesan cheese and red pepper flakes, whisking until cheese melts and sauce is smooth.

Add cooked pasta to the cream sauce, tossing to coat evenly. If sauce seems too thick, add reserved pasta water gradually.

Add fresh spinach to the pan, tossing gently until wilted and evenly distributed.

Return sliced chicken to the pan, folding gently into the pasta mixture.

Remove from heat and stir in fresh lemon juice. Taste and adjust seasoning with salt and pepper.

Serve immediately in warmed bowls, garnished with extra Parmesan cheese and fresh black pepper.

Provide lemon wedges on the side for guests who want additional brightness.