Now, a tuna melt is like, cooking 101-type stuff, right? Well, I don't know; tuna melts, like pancakes and omelettes, are simple in theory but take some time and practice to master (or at least they did in my case). Also, anyone can open a can of tuna, mix it up with some mayo, slather it on some wonder bread and call it a tuna sandwich. But it doesn't have to be that way. The tuna/mayo base is easy to fancy up, and usually you can do it with whatever you have on hand. To cut fat and add a little extra kick of flavor, I usually substitute a little Dijon mustard for some of the mayo. Some things I commonly add to tuna salad include (not necessarily together, mind you): sliced green olives, red onion, green onion, celery, diced apple, capers, nuts, cilantro, pickle, etc, etc. In this case I had a bunch of celery left over from when I made red beans and rice, and some chopped green onion that I kept forgetting to garnish my leftover sweet and sour pork with. I dumped this into my tuna, along with about a 1/2 tablespoon of capers for tang and some chopped almonds for crunch. A good sprinkling of fresh ground black pepper is a must for my tuna salad; sometimes I add a little dill as well.
To make a tuna melt:
Melt a pat of butter in a wide skillet over medium-low heat. Add your bread to the skillet and rub it around a bit to get some butter on it, then flip it over and rub it around again. Let your bread toast on one side until it starts to get golden. Flip it over and carefully spread your tuna mixture over one of the slices. I usually add something on top of that, like sliced onion or tomato or some baby spinach. Because I have arugula right now, I threw a handful on top of the tuna. Place your slices of cheese (I used Monterey Jack this evening) on top, close your sandwich, and press it down gently with the flat of a spatula to smoosh the different layers together. Reduce the heat to low and cover. When the cheese has started to melt, carefully flip the sandwich. I use two spatulas or other utensils to do this, sliding one under the sandwich and pressing the top down with the other. Cook on the other side until the cheese is nice and gooey.
For me, a tuna melt isn't really complete unless there's a side of tomato soup to go with it. If you have canned soup, that's fine, but I almost never get canned tomato soup because it is so easy to make, and homemade is much better. It's also better for you, because you can control how much salt goes in. Even the low-sodium soup brands have a lot of salt in them. Tomato soup is one of those gloriously minimalist foods. All you really need to do to make tomato soup is take a little can of tomato paste, mix it up in about two cups of water, season with salt and pepper, and heat through. I like garlic so I usually add some garlic, which I saute in a bit of olive oil before pouring the liquid in the pan. Beyond that, you can add pretty much whatever you want to your soup. I had extra grilled onion from my dinner last night, so I chopped that up and threw it in, and spiced it up with some cumin and paprika. Instant comfort food.