In a small bowl combine olive oil with garlic, thyme, mustard, lemon peel, salt and pepper. Rub into turkey breast.
Marinate in the refrigerator from 1 hour to 12 hours.
Arrange turkey breast, skin side up, on a baking sheet lined with parchment paper or tinfoil.
Roast at 350F for 50 to 60 minutes or until a meat thermometer inserted into the thickest portion of the breast reaches 165F and the juices run clear.
Remove turkey from oven to a carving board and tent with tinfoil. Place juices in a medium skillet (could drain off some of the fat) add lemon juice (perhaps use less if some of the fat drained off) and boil for 2 minutes. Remove from heat and stir in butter.
Carve turkey into thin slices across the breast. Drizzle with sauce and garnish with fresh thyme.