Heat 2 tablespoons of oil in a medium skillet over low heat.

Add the onion and cook, stirring occasionally, until it becomes translucent and tender, about 5 minutes.

Stir in the lima beans, cover, and cook for approximately 30 minutes or until the beans are soft.

Add the ham (if using) and cook for an additional 5 minutes.

Wipe the skillet clean afterward.

In a medium bowl, lightly beat the eggs with salt.

Mix in the cooked bean and onion mixture.

Let it rest for about 5 minutes.

Add the remaining 1 tablespoon of oil to the skillet and heat it over high heat until hot.

Quickly pour in the egg and bean mixture, spreading it evenly.

Reduce the heat to medium-high.

Cook, shaking the skillet often to prevent sticking, until the edges and bottom start browning, and the center is mostly set.

Use a spatula to carefully flip the omelet to the other side.

Add more oil to the skillet if needed.

Continue cooking until the center is fully set but slightly moist.