Preheat oven to 425˚F.
Pat dry turkey breast with paper towels. If you didn't brine it, and are just taking the turkey out, please remember to take out the giblets AND make sure that the turkey breast is completely thawed out.
Using the handle of a wooden spoon, carefully separate the skin from the turkey meat, moving downwards with the spoon’s handle. Loosen the skin from both sides of turkey breast. You can also just use your fingers to do this, but I find it easier with the spoon. Set aside.
Melt the butter and whisk in lemon juice, minced garlic, and chopped herbs.
Slowly pour the marinade inside the turkey’s skin and use your hands to massage it all around. Set aside.
In a small mixing bowl combine paprika, chili powder, garlic powder, onion powder, dried thyme, dried rosemary, salt, and fresh ground pepper; pour in olive oil and mix until well incorporated.
Slather the spice rub all over the turkey breast on the outside.
Add onion wedges, celery, garlic, and fresh thyme sprigs to a small roasting pan.
Top with turkey breast, skin side up. If making ahead, stop here; cover turkey with foil and refrigerate for up to 24 hours. Remove from fridge 1 hour before cooking.
Pour chicken broth into the pan.
Transfer to oven and reduce oven heat to 325˚F. Do not cover the turkey.
Bake for 2 TO 2.5 hours, or until internal temperature reaches 155˚F. About 18 to 20 minutes per pound. Use a meat thermometer to check for doneness.
If you want crispier skin, baste the turkey breast every 30 minutes.
If top of turkey breast starts to brown too quickly, loosely tent a piece of foil over the turkey breast and continue to roast.
When done, remove from oven and let stand 20 to 30 minutes before cutting.