I use to eat tuna the way my mom made it. Which is absolutely light and delicious, until I met my husband...I saw the way he made his but never thought i would even begin to like it seeing as that it has a bit of sweetness to it, and i had never ever grown up eating my tuna sweet in any way. My mom always made hers with seasonings and celery and onion....But one day i tried some of his tuna in a melt thinking that the cheese would be amazing with it...AND IT WAS AWESOME. I put a few differet seasonings in it than him and just made it my own and i like it his way and my own just the same. Now i pretty much only eat this tuna But of course on occasion at mom's I eat the tuna I still love and grew up with. They are polar opposites though I must say. I don't really measure my ingredients so it may be a little hit or miss. It all depends o how mayonaise-y you like it or how sweet. BUt i wil post al ingredients. I also love to serve these halves with Campbell's Tomato soup using heavy cream instead f milk and cooking slowly as not to burn. AMAZING. Especially on a cold night!
Flake all white albacore into bowl then add all above ingredients in a large bowl (excluding the avocado, cheese, tomato and bread). Mix well.
Slice tomatoes thinly, slice avocado's thinly, slice pieces of sharp cheddar and set aside.
butter both outsides of bread and then lay one butter side down on frying pan and add two big scoops of tuna mixture on bread and layer with sharp cheddar slices....let it get warm, then add two tomato slices and as much avocado as you like and then put the second piece of bread on top (butter side up) Flip when melting and brown both sides. ENJOY!!!!!!! I also like to serve this with Campbell's Tomato Soup but instead of using a large can of milk I use heavy cream instead. It's amazing!!!!