Preparing the Turkey Breast:

1. Prepare the Turkey Breast: Pat the turkey breast dry with paper towels. This helps the skin crisp up during roasting. Place the turkey breast on a cutting board, skin-side up.
2. Create a Pocket for Stuffing: Using a sharp knife, carefully cut a pocket into the side of the turkey breast. Start from the thicker side and slice horizontally, being careful not to cut all the way through to the other side or the bottom. You want to create a deep pocket that can hold the stuffing. Think of it like opening a book, creating a space inside.
3. Season the Turkey Breast: In a small bowl, combine the 2 tablespoons of olive oil, minced garlic (for turkey), dried thyme, dried rosemary, salt, and black pepper. Mix well to create a flavorful rub.
4. Rub the Turkey Breast: Rub the olive oil and herb mixture all over the outside of the turkey breast, including the skin. Make sure to also season the inside of the pocket you created for the stuffing. This ensures the turkey itself is flavorful and not just the stuffing.

Making the Spinach and Cheese Stuffing:

1. Sauté Aromatics: Heat 1 tablespoon of olive oil in a large skillet over medium heat. Add the diced onion and sauté until softened and translucent, about 5-7 minutes. Add the minced garlic (for stuffing) and sauté for another minute until fragrant. Be careful not to burn the garlic.
2. Wilt the Spinach: Add the roughly chopped fresh spinach to the skillet in batches. Cook, stirring frequently, until the spinach wilts down significantly. This will only take a few minutes. Once wilted, remove the skillet from the heat and let the spinach cool slightly.
3. Drain Excess Moisture: Once the spinach is cool enough to handle, squeeze out as much excess moisture as possible. This is crucial to prevent the stuffing from becoming watery. You can do this by pressing the spinach in a fine-mesh sieve or by squeezing it in your hands over the sink.
4. Combine Stuffing Ingredients: In a large bowl, combine the softened cream cheese, shredded mozzarella cheese, grated Parmesan cheese, breadcrumbs, drained spinach, sautéed onion and garlic mixture, and optional pine nuts or toasted walnuts and nutmeg (if using).
5. Mix the Stuffing: Mix all the ingredients together thoroughly until well combined. Season the stuffing with salt and freshly cracked black pepper to taste. Adjust seasonings as needed.

Stuffing and Roasting the Turkey Breast:

1. Preheat Oven: Preheat your oven to 375°F (190°C).
2. Stuff the Turkey Breast: Spoon the spinach and cheese stuffing into the pocket you created in the turkey breast. Pack it in firmly but not too tightly, as the stuffing will expand slightly during cooking.
3. Secure the Opening (Optional but Recommended): If desired, you can secure the opening of the turkey breast with kitchen twine or toothpicks to help keep the stuffing inside during roasting and maintain a neater presentation. This is especially helpful if you have a very large pocket and a lot of stuffing.
4. Sear the Turkey Breast (Optional but Enhances Flavor): Heat 1 tablespoon of olive oil in a large oven-safe skillet or Dutch oven over medium-high heat. Sear the stuffed turkey breast, skin-side down first, for about 3-4 minutes until the skin is nicely browned. Then, sear the other sides for about 1-2 minutes each. Searing adds depth of flavor and color. If you skip searing, you can place the turkey directly in the roasting pan.
5. Roast the Turkey Breast: Place the seared (or unseared) stuffed turkey breast in a roasting pan. If you seared it in a skillet, ensure it’s oven-safe, or transfer the turkey to a roasting pan.
6. Add White Wine (Optional): If using, pour the dry white wine into the bottom of the roasting pan. This will create flavorful pan juices.
7. Roast in the Oven: Roast in the preheated oven for approximately 1 hour 15 minutes to 1 hour 45 minutes, or until the internal temperature of the turkey breast reaches 165°F (74°C). Use a meat thermometer to ensure accurate doneness. Insert the thermometer into the thickest part of the turkey breast, avoiding the stuffing.
8. Check Internal Temperature: The turkey is done when a meat thermometer inserted into the thickest part of the breast (not touching bone or stuffing) registers 165°F (74°C). The stuffing should also be heated through to at least 165°F (74°C).
9. Rest the Turkey Breast: Once cooked, remove the turkey breast from the oven and transfer it to a cutting board. Tent loosely with foil and let it rest for at least 10-15 minutes. Resting allows the juices to redistribute throughout the turkey breast, resulting in a more tender and flavorful final product.