Agave-Glazed Turkey Breast with Sherry Gravy

Pat turkey breast dry and rub all over with 2 1/2 teaspoons sea salt and 1 teaspoon pepper. If you have the time, chill the breast in a baking dish, covered, overnight (see Cooks' Notes).

Let turkey stand at room temperature 1 hour.

Heat oven to 425°F with rack in lower third. Position turkey on rack in pan and roast 30 minutes.

Reduce oven to 400°F and scatter onion slices in bottom of roasting pan.

Add 1 cup water and continue to roast until thermometer inserted in thickest part of breast, close to but not touching bone, registers 160°F, 30 to 40 minutes.

While turkey is roasting, stir together agave nectar and vinegar in a small nonreactive saucepan and boil, stirring occasionally, until thickened and reduced to 3 tablespoons.

Remove from heat, but keep warm.

Brush glaze on turkey and roast until thermometer registers 165°F, 3 to 5 minutes.

Transfer turkey breast to a platter and let stand 15 minutes.

While turkey is standing, remove the rack, scraping off any yummy bits into the pan.

Straddle pan over 2 burners and add sherry, then deglaze pan by boiling sherry, stirring and scraping up browned bits, for 1 minute.

Strain liquid through a sieve into a heavy medium saucepan.

Add stock and bring to a boil. Reduce heat and keep at a simmer.

Meanwhile, whisk 1/2 cup water slowly into flour in a small bowl until flour slurry is smooth, then whisk in 1 tablespoon vinegar.

Add flour slurry to simmering stock, whisking, and bring gravy to a boil, whisking. Reduce heat and simmer, whisking, 3 minutes.

Season gravy with salt and pepper and additional vinegar, if desired.

Slice turkey breast and serve with gravy.

•Rubbing salt into a turkey is an easy way to come close to the juicy results you get from submerging a turkey in brine. This method also takes up less refrigerator space than brining does. If you don't have time to let the turkey sit overnight with the salt, don't worry. You will still end up with a delicious, juicy bird.•If you buy a kosher turkey, there's no need to let it sit overnight with the salt, because it's already had a similar treatment.•The easiest way to carve the turkey is to remove the two meaty breast halves in two separate pieces from either side of the breastbone and ribs, then slice them crosswise.