Rinse the dried corn and soak it in water overnight (at least 8 hours).
Drain and grind the soaked corn using a manual grinder or meat grinder with a coarse disc. The texture should be fine, but not like flour.
Knead the ground corn with a bit of water and salt until soft and pliable. Add achiote or turmeric if using.
Cover with a damp cloth and let rest while you prepare the filling.

Boil the potatoes in salted water until soft. Lightly mash them, leaving some chunks.
In a pan, sauté the scallion, garlic, and tomato in oil until soft.
Add ground beef, cumin, salt, and pepper. Cook until browned and fully done.
Mix the beef with the mashed potatoes and let it cool.

Take a ball of dough and place it between two pieces of plastic (cut-up plastic bag or plastic wrap).
Flatten into a thin circle using a tortilla press or plate.
Add a spoonful of filling in the center, fold into a half-moon, and press the edges to seal. You can use a cup or mold to help shape them neatly.

Heat oil in a deep pan to medium-high (about 350°F / 175°C).
Fry empanadas in batches until golden and crispy (about 5–7 minutes).
Drain on paper towel and it’s ready to eat