To begin, prepare the dough. In a large bowl, combine the precooked yellow cornmeal, salt, and warm water. Mix with your hands until a smooth, pliable dough forms. Add the vegetable oil and knead for 2-3 minutes. The dough should not crack when pressed; adjust with small amounts of water if necessary. Cover with a damp cloth to keep it moist.

Prepare the filling by boiling the diced potatoes in salted water until tender, about 10-12 minutes. Drain and mash lightly, leaving some texture. Set aside while preparing the meat mixture.

In a skillet over medium heat, heat the vegetable oil and sauté the onion, garlic, and tomato until softened, about 3-4 minutes. Add the ground beef or shredded chicken, season with cumin, paprika, salt, and pepper, and cook until the meat is browned and fully cooked. Mix in the mashed potatoes and stir to combine. Allow the filling to cool before assembling.

Divide the dough into equal-sized balls, about the size of a golf ball. Using a plastic sheet or parchment paper, flatten each ball into a thin circle, about 4 inches in diameter, using your hands or a rolling pin. To prevent sticking, grease the sheet lightly.

Place about 1-2 tablespoons of the filling onto one half of each dough circle. Fold the other half over the filling to create a half-moon shape. Seal the edges firmly by pressing with your fingers or a fork, ensuring no filling escapes.

Heat vegetable oil in a deep skillet or frying pan over medium-high heat until it reaches 350°F (175°C). Fry the empanadas in batches to avoid overcrowding, cooking for 3-5 minutes per side or until golden and crispy. Use a slotted spoon to remove and place them on a plate lined with paper towels to drain excess oil.

Check each empanada for a crispy exterior and ensure the filling is hot. Repeat the frying process with the remaining empanadas, adjusting the oil temperature if needed to maintain even cooking.

Serve the empanadas warm with a side of ají or lime wedges for added zest. Arrange them on a platter for a visually appealing presentation, garnished with fresh cilantro if desired. For an authentic experience, pair with a chilled beverage such as panela water or fresh juice.