The recipe I grew up with used relish and boiled eggs, salt and pepper in it along with miracle whip and I used to love, but as I matured though I've developed a resistance to relish so have needed to find a way to replicate the taste without side effects.
This had led to be playing around with what I like in my tuna melts.
My current rendition:
Ingredients:1 regular can of tuna, drained... for melts I like flaked tuna.
PC lemon-herb seasoning
2 pickled eggs
2 slices of bread
2 slices of cheese
Directions:Chop up the pickled eggs.
Then mix the rest of the first four ingredients in well. Add mayo and seasoning to taste. I tend to like a drier mix, others like wet.
Put on two slices of bread.
Cover with cheese slice (one for each slice of bread eh?)
Put in oven to heat through (350 if I recall until bread is browning basically), then under the broiler until cheese is all melty... or if you are like me until slightly burnt (if using the black diamond style cheese slices).
Works equally well in regular oven or a toaster oven.