Begin heating a large cast iron skillet on medium-low. In a shallow, flat-bottomed bowl, whisk together milk, eggs, rum or bourbon, nutmeg, and salt. Don’t skip the nutmeg as that will carry most of the eggnog flavor. Slice bread into 1.5” thick pieces. For every 2 slices of bread, add about ½ a tablespoon of butter to the skillet, making sure the bottom is evenly coated. Generously dip slices into the mixture, coating both sides. Cook for 1-2 minutes per side or until golden. Place on a baking sheet. Using a damp paper towel, quickly wipe down skillet. Repeat the process starting with the butter. If cooking ahead or for a large crowd, preheat oven to 200°F to keep french toast warm. Serve with pure maple syrup and a dusting of snow. If you’re looking for a fruit pairing, I’d suggest oranges.