Prep the chicken. Pat the cutlets dry.
In a shallow dish, mix flour, salt, pepper, garlic powder, and paprika. Dredge the chicken lightly, shaking off excess. Set aside on a plate.
Sear the chicken. Heat olive oil and 1 tbsp butter in a large skillet over medium-high.
Add chicken in a single layer and cook 3–4 minutes per side until golden and just cooked through. Transfer to a clean plate and tent loosely with foil.
Soften aromatics. Reduce heat to medium. Add remaining 1 tbsp butter.
Stir in shallot and a pinch of salt. Cook 2–3 minutes until translucent. Add garlic and cook 30 seconds until fragrant.
Deglaze the pan. Pour in white wine.
Scrape up browned bits with a spoon. Simmer 1–2 minutes to reduce slightly. If not using wine, add a splash of broth and a squeeze of lemon to brighten later.
Build the sauce. Stir in chicken broth and bring to a gentle simmer.
Pour in cream, then add a pinch of red pepper flakes if using. Simmer 2–3 minutes until slightly thickened.
Add spinach and cheese. Stir in the spinach by handfuls, letting it wilt. Once wilted, reduce heat to low and add Parmesan, stirring until melted and smooth.
Adjust thickness with a splash of broth if needed.
Finish with lemon. Add lemon zest and 1 tsp lemon juice. Taste and adjust with more salt, pepper, or lemon to balance the richness.
Return chicken to the pan. Nestle the cutlets into the sauce and spoon sauce over the top. Warm for 1–2 minutes.
Garnish with chopped parsley or basil.
Serve. Plate with pasta, mashed potatoes, rice, or crusty bread. Spoon extra sauce over the chicken.