01 - Pat chicken breasts dry with paper towels. Season both sides generously with salt and black pepper. Lightly dredge each breast in flour, shaking off excess to ensure even coating.
02 - Heat olive oil in large skillet over medium-high heat until shimmering. Add chicken breasts and sear 4 to 5 minutes per side until golden brown and cooked through to internal temperature of 165°F. Transfer chicken to plate and tent with foil.
03 - Reduce heat to medium. Add butter and minced garlic to skillet. Sauté until fragrant and garlic is pale golden, about 1 minute, being careful not to burn.
04 - Stir in sliced sundried tomatoes and cook for 1 minute to rehydrate and release flavors.
05 - Pour in chicken broth and bring to gentle simmer, using wooden spoon to scrape up browned bits from bottom of pan. Let reduce slightly for 2 minutes.
06 - Add heavy cream and grated Parmesan cheese. Stir continuously until cheese melts completely and sauce thickens enough to coat back of spoon, about 3 to 4 minutes.
07 - Add fresh baby spinach to sauce, stirring until just wilted but still vibrant green, about 1 minute.
08 - Return chicken breasts to skillet, spooning sauce generously over top. Simmer 3 to 4 minutes until chicken is heated through and flavors meld. Garnish with fresh basil if using. Serve immediately.