Heat 1 Tablespoon olive oil in a large skillet over medium-high heat.

Add the chicken pieces to the skillet and season with salt and freshly ground black pepper. Cook until the bottoms are golden brown, about 2–3 minutes; flip and cook another 2–3 minutes, until cooked through. Transfer the chicken to a plate.

Reduce heat to medium. Add 1 1/2 Tablespoons butter to the warm skillet and let it melt, scraping up any browned bits from the pan.

Add 3 teaspoons minced garlic and sauté about 20 seconds, until fragrant.

Pour in 1 1/2 cups low-sodium chicken broth and 1/4 cup water; stir to combine.

Add 10 ounces refrigerated cheese tortellini. Bring the liquid to a gentle boil or simmer, cover, and cook, stirring occasionally, until the tortellini are tender (about 2–4 minutes).

Add the 4 ounces Neufchatel cheese (cut into small pieces), 1/2 cup freshly grated Parmesan cheese, and 1 Tablespoon fresh lemon juice. Stir until the cheeses melt and form a creamy sauce.

Return the cooked chicken to the skillet and add 2 cups baby spinach leaves. Toss gently until the spinach wilts and the chicken is heated through. Taste and season with additional salt and pepper if needed.

Remove the skillet from heat, cover, and let rest for a few minutes to allow the sauce to thicken slightly and the spinach to finish wilting.

Serve warm (with extra Parmesan if desired).