Preheat the broiler and toast the whole wheat bread slices until lightly golden.

In a medium bowl, combine the drained chunk light tuna, minced shallot, reduced-fat mayonnaise, lemon juice, minced flat leaf parsley, salt, hot sauce, and freshly ground pepper. Mix until well combined.

Spread about 1/4 cup of the tuna mixture on each toast slice. Top with tomato slices and shredded sharp cheddar cheese.

Place the open-faced sandwiches on a baking sheet and broil for 3 to 5 minutes until cheese is melted and bubbly with golden-brown spots.