Rinse fresh dill and finely chop
Drain 1 can of tuna
Mix drained tuna, mayo, dill, shallot, vinegar and lemon in a bowl
Add s&p to taste
Place in fridge in an airtight container and let sit for a few hours or overnight (I find that the tuna always tastes best after all the flavors get to marinate a bit)
Right before you are ready to eat pre-heat the oven to ~250 F
Take 1-2 slices of bread and place 1 scoop of tuna salad mixture on top for an open-faced sandwich.
Add slice of each on top of each
Bake for a few minutes until cheese is melted
Take out of oven and enjoy!