1. In an 8-quart stockpot or other nonreactive container, combine 16 cups water with sugar, salt, unpeeled onion, unpeeled garlic, peppercorns, bay leaves, 1 bunch thyme, and 1 bunch parsley. Squeeze juice from both lemon halves into water and add lemon halves. Place stockpot on stove and bring to a boil over high heat. Reduce heat to medium and let simmer for 5 minutes. Remove from heat and let cool.

2. Add turkey breast to cooled liquid and refrigerate for 8 hours or up to overnight. Remove turkey from liquid, rinse, and pat dry. Place on a rimmed baking sheet lined with a wire rack; refrigerate until ready to cook, up to overnight.

3. Preheat oven to 400 degrees.

4. Melt 4 tablespoons butter. In a medium bowl, combine 2 cups peeled, chopped onion, celery, carrots, peeled garlic, sage, 4 sprigs thyme, and 1 tablespoon melted butter. Transfer vegetable mixture to the outer well of a vertical roasting pan. Fill the inner well of the pan with 1/2 cup chicken broth; pour remaining chicken broth over the vegetable mixture. Brush turkey breast with remaining 3 tablespoons melted butter; season with Essence and pepper. Position the turkey breast over the inner well of the vertical roasting pan so that it sits securely upright.

5. Transfer roasting pan to oven and cook until turkey is golden brown and an instant-read thermometer inserted into the thickest part of the breast reaches 165 degrees, about 1 hour. If the skin begins to brown too quickly, cover with parchment paper-lined foil.

6. Remove roasting pan from oven and transfer turkey breast to a carving board; let stand for 10 minutes before carving.

7. In a small bowl, stir together remaining 2 tablespoons butter and flour to make a smooth paste. Strain liquid from roasting pan and discard solids. Transfer liquid to a 3-quart saucepan. Bring to a boil over medium heat and whisk in 1 tablespoon of butter-flour mixture, taking care not to let it boil over. Whisk in remaining butter-flour mixture, 1 teaspoon at a time, and simmer until sauce is thick enough to coat the back of a spoon, about 1 minute. Remove jus from heat and stir in chopped parsley.

8. Carve turkey and serve with warm jus and Mushroom, Brown Butter, and Sage Stuffing.