You must start with a summer ripened tomato. Any color will do, but it has to be dead-ripe, succulent, and bursting with juice. It should never be refrigerated.
Next you need mayonnaise. If you don't like mayo, you are just plain up the creek without a paddle. I suppose you could drift along with olive oil, or nothing at all, but mayo is part of the magic of a perfect tomato sandwich.
The bread must be soft and yielding, never toasted, the better to absorb the mayonnaise and juice of the tomatoes. Last but not least, salt and freshly ground pepper are the essential seasonings.
Wash and dry your chosen tomato, and use your sharpest serrated knife to slice it. Go thick or thin (I like to pile them two high). Spread the mayonnaise on both slices, making sure it flows all the way to the edges, perhaps with an artful drip over the edge. Fit the tomatoes onto the sandwich as best you can.
Sandwich in hand, you may now move to the sink and start eating. Letting the juice run down your chin or your hands is handy for clean-up. Option two is to put your sandwich on a plate and take it out to the back stoop, where it can drip and run while you soak up the sunshine in which the tomato was grown. If you must sit at a table, don't forget napkins.
The first bite is all about texture -- the soft bread, the velvety emulsion of mayonnaise, the luscious tomato, bursting with juice – a unique and wonderful sensory experience. By the third bite, be ready for the harmony of flavors in which yeasty bread, creamy mayonnaise and tart-acid-sweet tomato come together, accentuated with spikes of salt and pepper. Don't hurry. Savor the flavors.
Tomato sandwiches are about as basic as you can get, but every one of them is satisfying and grounding. I eat them just about every day, for breakfast, lunch, dinner, or in between. And every last one of them is perfect.