Ingredients You’ll Need
For the Stuffed Chicken:
- 4 boneless, skinless chicken breasts (about 6-8 ounces each) – look for breasts of similar size for even cooking
- 1 packet (10 oz) frozen chopped spinach, thawed and thoroughly drained – fresh spinach works too (see variations)
- 1 cup grated mozzarella cheese or a mix of mozzarella and parmesan for extra flavor depth
- 1 clove garlic, minced – fresh is best for maximum flavor
- ½ teaspoon salt – adjust to taste
- ¼ teaspoon black pepper – freshly ground if possible
- 1 tablespoon Dijon or whole grain mustard – this adds a subtle tang and helps seal in moisture
Optional Add-ins for Customization:
- ¼ cup sun-dried tomatoes, chopped – adds a sweet, concentrated tomato flavor
- ¼ cup mushrooms, finely chopped and sautéed – brings earthy depth
- ¼ cup fresh parsley, chopped – for brightness and color
- 2 tablespoons cream cheese – makes the filling extra creamy
- ¼ teaspoon red pepper flakes – for those who enjoy a gentle heat
- 1 tablespoon fresh basil, chopped – pairs beautifully with the Italian-inspired flavors
For Enhanced Flavor (Optional but Recommended):
- 2 tablespoons olive oil or melted butter – for brushing the chicken before baking
- Paprika or Italian seasoning – for sprinkling on top
- Fresh lemon wedges – for serving
Kitchen Tools & Equipment
- Sharp knife for butterflying the chicken
- Cutting board
- Medium mixing bowl
- Toothpicks or kitchen twine for securing
- Baking dish (9×13 inch works perfectly)
- Meat thermometer (highly recommended for perfect results)
- Paper towels for draining spinach
- Pastry brush for applying mustard
Step-by-Step Method
Prep Work (10 minutes)
1. Prepare Your Oven and Workspace Preheat your oven to 375°F (190°C). This temperature is ideal for cooking the chicken through while keeping it moist and allowing the cheese to melt beautifully without burning. Line your baking dish with parchment paper or lightly grease it with olive oil to prevent sticking.
2. Drain the Spinach Thoroughly. This step is crucial and often overlooked! Place your thawed spinach in a clean kitchen towel or several layers of paper towels. Twist and squeeze firmly to remove as much liquid as possible. Excess moisture will make your filling watery and prevent the cheese from binding properly. You should remove at least ¼ cup of liquid. Set the spinach aside in a bowl.
3. Prepare the Filling In your mixing bowl, combine the well-drained spinach, grated cheese, minced garlic, salt, and black pepper. Mix thoroughly until everything is evenly distributed. The mixture should hold together when pressed. If you’re adding any optional ingredients like sun-dried tomatoes, mushrooms, or parsley, fold them in now. Taste the mixture (it’s safe since there’s no raw meat) and adjust seasoning if needed.
Preparing the Chicken (10 minutes)
4. Butterfly the Chicken Breasts. Place one chicken breast on your cutting board. Using a sharp knife, carefully slice horizontally into the thickest part of the breast, cutting almost all the way through but leaving about ½ inch attached on one side – think of creating a book that opens. Open the breast like a book and gently pound it with a meat mallet or the bottom of a heavy pan to an even thickness of about ½ inch. This ensures even cooking and creates more surface area for the filling. Repeat with the remaining breasts.
Pro Tip: If butterflying feels intimidating, you can also create a deep pocket by cutting horizontally into the thick side of the breast, being careful not to cut all the way through.
5. Season and Prepare Pat the chicken breasts dry with paper towels – this helps the mustard and seasonings adhere better. Using your pastry brush, apply a thin layer of mustard sauce to the inside surfaces of each butterflied breast. This not only adds flavor but also helps keep the chicken moist during baking. Lightly season the inside with a pinch of salt and pepper.
Stuffing and Securing (5 minutes)
6. Stuff the Chicken Divide your spinach and cheese mixture evenly among the four chicken breasts, placing it on one side of the opened breast. Use about ¼ to ⅓ cup of filling per breast – don’t overstuff or it will leak out during cooking. Leave about ½-inch border around the edges to help seal.
7. Roll and Secure Carefully fold the chicken breast over the filling, pressing the edges together to seal. Secure with 2-3 toothpicks inserted at an angle, or tie with kitchen twine at 1-inch intervals. The goal is to keep the filling enclosed while the chicken cooks. Brush the outside of each stuffed breast with the remaining mustard, or use olive oil or melted butter. This creates a beautiful golden exterior. Sprinkle with paprika or Italian seasoning if desired.
8. Arrange in Baking Dish Place the stuffed chicken breasts seam-side up in your prepared baking dish, leaving a little space between each one for even heat circulation.
Cooking (25-30 minutes)
9. Bake to Perfection Place the dish in your preheated oven and bake for 25-30 minutes. The exact time will depend on the thickness of your chicken breasts. The chicken is done when:
- The internal temperature reaches 165°F (74°C) when measured with a meat thermometer inserted into the thickest part
- The juices run clear when pierced
- The cheese is melted and bubbling
- The exterior is golden brown
Important: Avoid overcooking, as this will result in dry chicken. A meat thermometer is your best friend here!
10. Rest Before Serving Remove from the oven and let the chicken rest for 5 minutes before removing toothpicks and serving. This allows the juices to redistribute throughout the meat, ensuring every bite is moist and flavorful.
Serving Suggestions
This elegant stuffed chicken pairs beautifully with:
- Roasted vegetables – asparagus, broccoli, or Brussels sprouts
- Creamy mashed potatoes or cauliflower mash for a low-carb option
- Simple side salad with a light vinaigrette
- Garlic bread or warm dinner rolls
- Rice pilaf or quinoa for a wholesome grain option
- Steamed green beans with almonds
Garnish with fresh parsley and serve with lemon wedges for brightness. A light drizzle of balsamic reduction or a simple pan sauce made from the baking dish drippings elevates this dish even further.
Storage and Meal Prep Tips
Refrigeration: Store leftover stuffed chicken in an airtight container in the refrigerator for up to 3 days. Reheat gently in a 350°F oven until warmed through, or slice and reheat in the microwave.
Freezing: You can freeze the stuffed, uncooked chicken breasts! Wrap each one individually in plastic wrap, then place in a freezer bag. Freeze for up to 3 months. Thaw overnight in the refrigerator before baking as directed (you may need to add 5-10 minutes to the cooking time).
Make-Ahead: Prepare the chicken through step 8, cover tightly with plastic wrap, and refrigerate for up to 24 hours before baking. This is perfect for entertaining!
Variations to Try
Greek-Inspired: Use feta cheese instead of mozzarella, add chopped Kalamata olives and oregano to the filling.
Caprese Style: Add chopped fresh tomatoes and basil to the filling, and use fresh mozzarella.
Artichoke Lover’s: Mix in chopped artichoke hearts and use a blend of parmesan and gruyere.
Pesto Perfection: Spread a thin layer of pesto inside the chicken before adding the spinach mixture.
Fresh Spinach Option: Use 4 cups fresh spinach, sautéed until wilted and cooled, instead of frozen.
Creamy Upgrade: Add 2-3 tablespoons of cream cheese or ricotta to the filling for extra richness.
Troubleshooting Common Issues
Problem: Filling leaks out during cooking. Solution: Don’t overstuff, secure well with toothpicks, and make sure spinach is thoroughly drained
Problem: Chicken is dry. Solution: Don’t overbake – use a meat thermometer and remove at exactly 165°F. The mustard coating helps prevent drying.
Problem: Filling is watery. Solution: This almost always comes from not draining the spinach enough. Really squeeze it dry!
Problem: Chicken cooks unevenly. Solution: Pound to even thickness and choose breasts of similar size
Nutritional Benefits
This recipe offers impressive nutritional value:
- High in protein from the chicken (about 35g per serving)
- Rich in iron and vitamins A, C, and K from spinach
- Good source of calcium from the cheese
- Low in carbohydrates – perfect for keto and low-carb diets
- Provides selenium and B vitamins essential for metabolism
Each serving contains approximately 320-380 calories (depending on cheese amount), making it a satisfying yet reasonable dinner option.