Spread the mustard on each of the cut sizes of the rolls. Place a slice of cheese and watermelon on top of each roll bottom and divide the sprouts over the watermelon slices. Place the top of the roll over the sprouts.

* Smoked fresh mozzarella cheese can be found with specialty or gourmet cheeses at most supermarkets. It comes in ovals about 3 inches in diameter, which is the perfect size for this recipe. If the smoked mozzarella available in your market is larger, cut in half and use half-moon shapes. Plain fresh mozzarella can be substituted but the smoky flavor is terrific in the recipe. If you use plain fresh mozzarella cheese, add a drop or two of liquid smoke to the honey Dijon.

Source:

Watermelon.org