Tandoori Turkey

Toast spices in a skillet over medium heat, swirling often, until fragrant, about 2 minutes. Let cool. Working in batches, finely grind mixture in a spice mill. DO AHEAD:

Toast spices in a skillet over medium heat, swirling often, until fragrant, about 2 minutes. Let cool. Working in batches, finely grind mixture in a spice mill. Sift through a medium-mesh strainer into a small bowl; stir to combine. DO AHEAD:

Pat turkey dry with paper towels. Rub inside and out with salt; transfer to roasting bag. Stuff turkey with cardamom pods and cumin seeds, then onion, celery, and garlic.

Puree all ingredients in a blender. Pour marinade into roasting bag. Smear all over turkey. Tie bag and arrange turkey, breast side down, in a large heavy roasting pan. Refrigerate overnight.

Let turkey stand in bag at room temperature for 1 hour. Turn breast side up. Create steam holes in bag if required by manufacturer's instructions.

Preheat oven to 400u00b0F. Roast turkey for 30 minutes. Reduce heat to 350u00b0F. Roast until an instant-read thermometer inserted into thickest part of thigh (puncturing bag with thermometer) registers 160u00b0, about 1 1/2 hours longer. Cut top of bag open, being careful of steam and juices, and pull back over turkey. Roast turkey until breast is deeply browned but not burned and a thermometer inserted into thigh registers 165u00b0F, 15-30 minutes longer.

Transfer to a platter. Let rest for at least 20 minutes before carving.

Meanwhile, strain juices into a large saucepan. Spoon fat from surface. Simmer over medium heat until sauce is reduced to 3 1/2 cups, about 20 minutes.

Carve turkey. Serve with accompanying gravy.