Heat the vegetable oil in a large skillet over medium heat.

Add the ground beef to the skillet and cook, breaking it up with a spoon, until it is no longer pink and lightly browned, about 5 to 7 minutes. Drain excess fat if necessary.

Stir in the finely chopped white onion and cook for 2 to 3 minutes until it softens and becomes translucent.

Add the minced garlic and cook for about 30 seconds, stirring constantly so it does not burn.

Add the diced potatoes to the skillet and stir to coat them with the beef and aromatics.

Stir in the chopped Roma tomatoes and tomato sauce, mixing well so everything is evenly combined.

Pour in the beef broth or water and stir, scraping the bottom of the skillet to release any browned bits.

Season the mixture with ground cumin, dried oregano, ground black pepper, and salt, stirring until the spices are well distributed.

Reduce the heat to low, cover the skillet with a lid, and let the picadillo simmer for 15 to 18 minutes, stirring occasionally, until the potatoes are tender and the sauce has slightly thickened.

Stir in the frozen peas, cover again, and cook for 3 to 4 more minutes until the peas are heated through and tender.

Turn off the heat and stir in the chopped fresh cilantro. Taste and adjust salt if needed before serving.