Very easy recipe, and leaves quite a bit of room to experiment with. Try it with your own touches, such as topped with chopped Parsley, green onions, etc., or even using lump crab meat instead of tuna. Let me know what you think!
Starting with the tomatos, cut each one in half lengthwise. Next, using a small spoon, scoop out the seeds and water. place each half face down on a paper towel to help drain the water while you're working with the other ingredients. Spinkle each tomato half with a small pinch of salt.
Boil the egg(s) until hard-boiled. Length of time will greatly depend on your location with respect to altitude.
Some people like to drain their tuna, especially if it's canned in water, but if you are using tuna canned in oil and NOT draining it, I recommend using slighly less than one cup of mayo, so your mixture doesn't get too runny. That could be bad...
Add your pickle, onion, mayonnaise, tuna, and hard-boiled egg in a mixing bowl and combine with a fork or potato-masher. Instrument used will greatly depend on your mood that day(!)
Spoon your tuna salad into the tomato halfs, as much or as little as you like, and top each with a garnish of your choice.
With any luck, you'll have enough for a small sandwich to celebrate your undertaking! Have fun, and let me how it turns out for you!