Make the mayonnaise by adding the Sriracha and mayonnaise together. Stir well, and set it aside.
To a medium sized mixing bowl, add in the tuna, and flake it with a couple of forks, leaving some chunks. Toss in the lemon juice, shallot, cilantro, garlic, serrano chili, beaten eggs, roasted tomatoes, bread crumbs, and salt and pepper. Pretty much everything else but the olive oil.
Mix that with a fork, ensuring that everything is well incorporated.
Now it is time to shape our tuna cakes. I'm a big fan of these plating rings, but if you do not have any food preparation molds, basically divide the tuna mixture into three even cakes, and shape them into patties.
Heat a non-stick skillet to medium heat. Add one tablespoon of the oil to the center, and swirl it about the diameter of the formed caked.
Add the tuna cake to the center of the skillet, and cook for a few minutes. After a few minutes, cover, and cook an additional minute.
Carefully flip the tuna cake over, reduce the heat a bit, and cook another few minutes, then cover another minute.
If you are using the mold ring, and are ready to plate, take the tuna cake and place it on your serving plate. Run a sharp knife along the interior in case the tuna cake tries to stick and lift up the mold. If you are not using the mold, simply use a spatula and lift that on to your serving dish.
Drizzle with the Sriracha mayonnaise, and serve with some fresh lettuce.