In a glass bowl, toss the flaked tuna with the mayonnaise, mustard, celery, onion, relish, brine and grated cheddar.
1 cup albacore tuna, 1/4 cup mayonnaise, 1 tsp Dijon mustard, 1/4 cup celery, 3 tbsp red onion, 1 tbsp pickle relish, 1 tbsp pickle brine, 1 cup cheddar cheese
Add the bread slices on top of a foil lined baking sheet. Lightly toast the bread slices under the broiler.
2 slices sourdough bread
Add a slice of cheddar to each piece of toast, then return to the broiler for about 2 minutes to melt the sliced cheese.
4 slices cheddar cheese
Carefully remove, then add a generous scoop of the tuna mixture to each piece of cheesy toast. Return to the broiler, just until the grated cheddar in the tuna mixture begins to melt.
Carefully remove from the broiler again, top with cherry tomato halves and dill, plus a sprinkle of salt and pepper to taste.
1 cup cherry tomatoes, 1 tsp kosher salt, 1/2 tsp black pepper, 1 tbsp fresh dill
Serve open faced with a fork and knife.