Heat 2 tablespoons of oil in a 10-inch skillet over medium heat.

Add the onion and cook until softened, about 5 minutes.

Add the chorizo, ham, and potatoes, stirring occasionally for another 5 minutes.

Add the pimientos, beans, peas, and asparagus, cook and stir for an additional 5 minutes.

Wipe the skillet clean after this step.

In a large bowl, lightly beat the eggs with a fork.

Fold in the skillet mixture and season with salt.

Heat 1 tablespoon of oil in the same skillet over high heat until it's hot.

Pour in the egg and vegetable mixture, spreading it evenly.

Reduce the heat to medium-high.

Cook, shaking the skillet often to avoid sticking, until the edges and bottom begin to brown, and the center is mostly set.

Slide the omelet onto a plate, cover it with another plate, and carefully flip it over.

Add the remaining teaspoon of oil to the skillet and return the omelet to it.

Cook until the bottom is nicely browned and use a spatula to tuck in the edges for a neat appearance.

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