Add the drained tuna, dill, red onion, celery, mayo, and boiled eggs. Stir until thoroughly combined. Add salt and pepper to taste.
Preheat oven to 400 degrees.
Spread butter on one side of each slice of bread. Place 4 slices on a baking sheet with the buttered side facing down.
Spread some tuna salad on each slice of bread, and add 2 slices of American cheese on top. Then, lay the top slice of bread butter-side down on the baking sheet.
Bake for 10 minutes until the bread is golden and the cheese is melted.
Add lettuce, tomato, and pickles. Then add the top slice of bread.
Slice the sandwiches in half and serve immediately. Enjoy!