How do you prevent the filling from leaking out when cooking?
Pat the chicken dry, create a pocket carefully without cutting through, pack the filling firmly, and secure the opening with toothpicks if needed. Start cooking on medium-high heat to seal the exterior quickly.
What temperature should stuffed chicken breast reach?
Cook until the internal temperature reaches 165°F (74°C) at the thickest part, measured with a meat thermometer away from the filling.
Can you make this ahead?
Yes—assemble and stuff the chicken breasts up to 24 hours ahead, cover, refrigerate, then cook from cold (add 2–3 minutes to cooking time).
What if your spinach is still wet after thawing?
Squeeze it very firmly in a clean kitchen towel or paper towels until no excess moisture remains; wet spinach will dilute the filling and make it soggy.
Can you use fresh spinach instead of frozen?
Yes—use 4 cups fresh spinach, sauté in a pan until wilted, cool, then squeeze dry before mixing into the filling.