Pour the eggnog into a small saucepan and sprinkle the gelatin evenly over the surface. Let it sit undisturbed for 5 minutes—this allows the gelatin to absorb the liquid and bloom, which ensures a smooth, lump-free texture when heated. Don't stir during this time; patience here prevents clumping later.

Place the pan over medium-high heat and whisk constantly until the gelatin completely dissolves and the eggnog reaches a gentle simmer—you'll see small bubbles forming around the edges. This takes about 3-5 minutes. I find that whisking continuously prevents the bottom from scorching and ensures even heat distribution, which gives you the silkiest final texture.

Remove the pan from heat and immediately pour the warm eggnog mixture into serving glasses, filling each about halfway. Transfer to the refrigerator and chill for at least 2 hours, or until the panna cotta is set and has a delicate, custard-like consistency. You can make these up to 24 hours ahead if needed.

Just before serving, use a microplane or fine grater to grate fresh nutmeg generously over the top of each panna cotta. The freshly grated nutmeg releases essential oils that create an aromatic warmth and complements the creamy eggnog beautifully—it's worth taking the extra 30 seconds to grate it fresh rather than using pre-ground.