In the same skillet, with the heat returned to medium, add the lemon juice and butter. Use a wooden spoon to scrape up the flavorful browned bits from the bottom of the pan. Stir in the minced garlic and cherry tomatoes, and sauté briefly—just a minute or two—until the tomatoes begin to soften and release their juices. You can also add finely diced onions at this stage, if desired.
Pour in the heavy cream and chicken broth. Whisk well to blend and let the sauce come to a gentle simmer for 2 to 3 minutes.
Add the cream cheese and grated Parmesan, continuing to whisk until the sauce becomes smooth and begins to thicken. Season to taste with salt and freshly ground black pepper.
Fold in the chopped spinach, fresh basil, and parsley, allowing them to wilt slightly and infuse the sauce with herbaceous aroma.
Return the cooked chicken to the pan, nestling it into the creamy Tuscan sauce. Spoon the sauce over the chicken and allow it to heat through for a minute or two before serving.