Mix sweetener, lime juice, fish sauce, sliced lemongrass, and sliced chili in a small bowl. Set dressing aside.
In a small bowl, combine the roughly chopped tomatoes, cucumber, sliced onion, and chopped cilantro. Set aside.
To a large pan, add about ¼ cup of oil. Crack in all three eggs and fry until golden brown and crispy. Flip and fry for another minute until yolks are just set. Remove the egg from the pan and roughly chop it into large pieces.
Toss the egg into the salad and pour over some of the dressing (all the dressing will not be used) Adjust seasonings by adding salt or more fish sauce.