Preheat oven to 400°F.

Combine 1½ tablespoons butter, sage, thyme, lemon zest, salt, and pepper in small bowl and mash with fork. Spread butter mixture all over turkey.

Place turkey in small roasting pan or large ovenproof skillet; pour ¾ cup broth around turkey and add garlic cloves to pan. Roast turkey, uncovered,basting turkey and turning garlic cloves twice, until turkey is cooked through and instant-read thermometer inserted into thickest part registers 165°F, about 45 minutes. Transfer turkey to cutting board, cover loosely with foil, and let rest 10−15 minutes.

Meanwhile, remove garlic from pan. Peel garlic cloves. Place roasting pan or skillet with turkey drippings on stovetop over high heat; add garlic cloves, remaining ¾ cup broth, and lemon juice. Bring mixture to boil, scraping bottom of skillet to incorporate drippings; continue boiling until sauce reduces and thickens slightly, mashing garlic to blend into sauce, 2−3 minutes. Remove from heat and strain sauce into small bowl; swirl in remaining 1½ tablespoons butter until melted.

Cut turkey into about 24 slices and arrange on serving platter; drizzle with any drippings from cutting board. Spoon sauce over turkey or serve on the side; garnish with more fresh lemon zest and chopped sage if desired.