Wash hands with soap and water.
Preheat oven to 375°F.
Unroll the crescent roll dough onto your kitchen work surface. Firmly press diagonal perforations to seal and separate into 4 long rectangles.
Place 2 deli ham slices on each of the rectangles.
Spread 1 teaspoon of Dijon mustard on each rectangle and sprinkle with 1/4 cup of Swiss or cheddar cheese.
Starting at the shortest side, roll up each rectangle, press and seal. Optional: Coat each roll with sesame seeds.
Cut each of the 4 rolls into5 slices forming 20 slices. Place cut side down on an ungreased cookie sheet.
Wash hands with soap and water.
Bake the rolls in the preheated oven until the internal temperature reaches 140°F on a food thermometer and the crescent is golden brown.