1. Cook ham, in 3 batches, in a large stainless-steel skillet (do not use nonstick) over medium heat 4 to 5 minutes on each side or until browned. (The skillet will be dry.) Remove ham from skillet.
2. Melt butter in skillet. Stir in cola and 1⁄2 cup water, and simmer 3 minutes, stirring with a spatula to loosen particles from bottom of skillet. Serve hot gravy with ham.