Remove wrapping and plastic insert from turkey and discard. Take out giblets and neck and set aside. Rinse turkey well under cold running water and pat dry.
In a small bowl, combine salt, paprika, cumin and coriander. Sprinkle seasoning mix all over turkey - inside cavity and over skin - especially the breast and top side.
Put a handful of diced onion, the lemon wedge and the herbs in the cavity. Set aside.
In the bottom of the roasting pan just larger than the turkey, place the remaining onions, carrots, celery, giblets and turkey neck. Set turkey on a rack over top. Add broth and about 1 cup water; add more water if needed so that liquid covers vegetables but doesn't touch the turkey.
Tent turkey loosely with foil and roast, breast side up, for about 3 1/2 hours or until the thickest part of the thigh registers 175F on an instant-read thermometer. Check periodically, adding water to the pan if it looks dry. Remove foil for last hour of cooking, rotating turkey halfway through if top is browning unevenly.
Transfer cooked turkey to a platter (internal temperature should rise to 185F) and allow to rest for 15-20 minutes.
GRAVY: Pour contents of roasting pan through fine mesh strainer set over a large measuring cup or work bowl. Place roasting pan on stovetop. Add 1/2 cup chicken broth and over low heat, stir liquid until brown bits have been lifted. Pour through a strainer, adding to accumulated liquid.
With the back of a spoon press solids against strainer until all their liquid is released. Discard solids and skim fat from pan juices. Add enough chicken broth to make up 4 cups stock.
In a medium, heavy bottom saucepan, melt butter over low heat. Add flour and stir mixture until lightly golden, about 5 minutes. Whisk in stock, a little at a time, over low heat, Once all the stock is incorporated, heat the gravy gently, whisking until smooth Add balsamic vinegar and thyme. Adjust seasoning if necessary.
Carve turkey and serve with gravy. HAPPY HOLIDAYS!