In a large pot, combine 8 cups water, kosher salt, brown sugar, bay leaves, peppercorns, smashed garlic, thyme and rosemary. Bring to a simmer over medium heat, stirring until salt and sugar dissolve. Remove from heat and cool to room temperature.

Cool and chill

Once brine is room temperature, add 2 cups of ice to speed cooling. Transfer to the refrigerator if needed so the brine is cold before adding the turkey (target under 40°F / 4°C).

Brine the turkey

Place the 3 lb boneless skin-on turkey breast in a non-reactive container or resealable bag. Pour the cooled brine over the turkey, ensuring it is fully submerged. If necessary, weigh it down with a plate. Refrigerate for 6–8 hours (no more than 12 hours).

Rinse and dry

After brining, remove the turkey from the brine. Rinse thoroughly under cold water to remove excess surface salt. Pat the breast very dry with paper towels. Let rest on a rack in the refrigerator, uncovered, for 1 hour if time allows to dry the skin (this helps browning).

Seasoning & Basting

Prepare butter mixture

In a small bowl, combine 4 tbs softened unsalted butter, 1 tbs olive oil, lemon zest and 1 tbs lemon juice, 2 minced garlic cloves, 2 tbs chopped parsley, 1 tsp thyme leaves, 1 tsp black pepper and 1/2 tsp kosher salt. Mix until smooth and homogenous.

Loosen skin and apply

Place the turkey breast skin-side up. Gently loosen the skin from the meat using your fingers, creating pockets without tearing. Spread about half of the butter mixture directly onto the meat under the skin, distributing evenly. Rub the remaining butter mixture over the exterior skin.

Roasting & Serving

Preheat oven and prepare pan

Preheat oven to 425°F (220°C). In a roasting pan or ovenproof skillet, spread the quartered onion, carrot chunks and celery to form a bed. Place a rack on top if available and set the turkey breast on the rack (skin-side up). Pour 1 cup of stock into the pan around the vegetables (not over the breast).

Initial high-heat roast

Roast at 425°F for 20 minutes to crisp and brown the skin.

Reduce heat and continue roasting

After 20 minutes, reduce oven temperature to 350°F (175°C). Continue roasting until the internal temperature in the thickest part of the breast (not touching bone) reaches 160°F (71°C). For a 3 lb boneless skin-on breast this will typically take an additional 30–45 minutes; start checking at 30 minutes. Baste once or twice with pan juices during the last 20 minutes if desired.

Rest the turkey

When the internal temperature reaches 160°F, remove the turkey from the oven and tent loosely with foil. Let rest for 15–20 minutes; carryover will raise the temperature to about 165°F and juices will redistribute.

Make pan sauce (optional)

While the turkey rests, place the roasting pan with vegetables and juices on the stovetop over medium heat. Skim excess fat if desired. Add 1/2 cup additional stock or water, scrape up browned bits with a wooden spoon, and simmer 3–5 minutes. Strain into a gravy boat or saucepan, adjust seasoning to taste, and keep warm.

Carve and serve

Transfer the turkey breast to a cutting board. Slice crosswise into 1/4–1/2 inch slices against the grain. Arrange on a platter, spoon pan sauce over if using, and garnish with 1 tbs chopped parsley. Serve warm.