Step 1: Prepare the brine: In a large pot, combine 8 cups of water with 1/2 cup of kosher salt, 1/4 cup of brown sugar, 2 bay leaves, 1 tablespoon of black peppercorns, and 2 sprigs each of fresh rosemary and thyme. Bring to a simmer over medium heat, stirring until salt and sugar dissolve. Remove from heat and cool completely.
Step 2: Submerge the turkey breast in the cooled brine. Ensure it’s fully covered (use a plate to weigh it down if necessary). Refrigerate for 4-6 hours.
Step 3: While turkey brines, prepare herb butter: In a small bowl, combine 1/2 cup softened unsalted butter with 2 tablespoons each of finely chopped fresh rosemary, thyme, and sage, 2 cloves minced garlic, 1 teaspoon smoked paprika, and 1/2 teaspoon black pepper. Mix thoroughly.
Step 4: After brining, remove turkey from liquid and pat completely dry with paper towels. Place on a roasting rack set inside a roasting pan.
Step 5: Gently separate the skin from the breast meat with your fingers. Spread about half of the herb butter mixture directly onto the meat under the skin. Rub the remaining herb butter all over the exterior of the skin.
Step 6: Preheat oven to 400°F (200°C). Roast turkey breast for 20 minutes at this temperature.
Step 7: Reduce oven temperature to 350°F (175°C). Continue roasting for 60-90 minutes, or until an instant-read thermometer inserted into the thickest part of the breast (without touching bone) reads 165°F (74°C). Tent with foil if browning too quickly.
Step 8: Remove from oven, tent loosely with foil, and let rest for at least 15-20 minutes before carving. This ensures juicy results.