Creamy lemon chicken with spinach

1. Slice the chicken breasts horizontally (similar to a butterfly cut) all the way through to create two thinner pieces. To do this, place your hand flat on top of the chicken breast to keep it steady, and use a sharp knife to carefully cut through the middle from one side to the other. Place the chicken pieces side by side on a cutting board and cover with plastic wrap. Gently pound with the smooth side of a meat mallet until even thickness. Season both sides of the chicken with salt and pepper.
2. Place the flour on a large plate. Working with one at a time, coat both sides of each piece of chicken in the flour.
3. In a large skillet, heat the olive oil over medium-high heat. Add the chicken in one layer and cook, undisturbed, until golden brown, about 3 mins per side. Remove the skillet from the heat and transfer the chicken to a large plate. Cover to keep warm.
4. Return the skillet to the stove over medium heat and add the chicken broth. Cook, scraping up any bits stuck to the pan, until it reduces by about half (2-3 mins). Add the garlic and cook 1 min until fragrant, then add the cream cheese. Whisk the cream cheese until it melts into the sauce (2-3 mins), then whisk in the milk 1/2 cup at a time, stirring to fully incorporate it after each addition.
5. Season with 1/2 tsp kosher salt and 1/4 teaspoon pepper and continue cooking for 1-2 more mins until the milk gets heated through. Stir in the spinach and cook for 1-2 mins until just wilted, then turn off the heat and stir in the lemon juice and lemon zest. Taste and adjust seasoning if desired.
6. Return the chicken to the skillet, nestling it in the sauce. Serve with sauce spooned on top and enjoy!