Position a rack 4 inches from the broiler element and heat the broiler on high.
In a medium bowl, combine the tuna, tomato, red onion, olives, dill, vinegar, olive oil, anchovy, 1/4 tsp. salt, and a few grinds of pepper.
Put the bread on a rimmed baking sheet and broil until nicely toasted, 30 seconds to 1 minute. Remove the pan from the broiler, flip the bread over, and spread the tuna mixture evenly over each slice. Sprinkle the cheese evenly over the tuna and continue to broil until the cheese is melted and beginning to brown, 1 to 2 minutes. Serve.
Serve with Roasted Fingerling Potato Crisps on the side.
nutrition information (per serving):
Photo: Scott Phillips