Slice your baguette and arrange the pieces of bread on a serving plate. You can use the bread fresh, or make a crostini. Make a crostini by brushing the baguette slices with a bit of olive oil on one side. Broil on high for 1-2 minutes until just beginning to turn brown on the edges. Remove from the heat and let them cool before adding the toppings.
Use a butter knife to spread red pepper jelly onto each slice of baguette.
Place 1 slice of gouda or Havarti cheese on top of the piece of bread.
Place 1-2 pieces of arugula on top of the cheese layer.
Add 1 piece of prosciutto on top of the arugula. Prosciutto is best presented if it is folded over onto itself. It makes the appetizer look a bit more fancy.
Drizzle a small amount of balsamic reduction on top of the prosciutto appetizer.
Serve immediately or store in the fridge prior to serving. Make sure to cover it with cling wrap if you need to place it in the fridge.