After resting, place the breast on a cutting board. Use a sharp knife—please don’t use a butter knife—and slice against the grain. That means across the lines of the muscle fibers.
Slice off the whole breast from the bone in one piece, then cut it into ½-inch thick slabs. Arrange them on a platter, pour a little pan juice over the top, and watch your friends swoon.
You did it. You cooked a beautiful, 8-pound turkey breast without a panic attack. Go you.