Cook the steak. Coat the bottom of a large sauté pan with olive oil and sprinkle both sides of the steak with salt and pepper. (A cast iron skillet is best.) Place the pan over high heat and once it's very hot, add the meat. You should hear a sizzling sound -- if you don't, the pan isn't hot enough yet. Wait until it is. Sear both sides of the meat to brown it, then turn the heat to medium-low to finish the cooking, about 15 minutes for medium. Once the meat is cool enough to touch, shred it with your hands, and then chop it finely. Set aside. You can do this the night before you're serving if desired, keeping it covered in the refrigerator. Either way, do not wash the pan! If it's the night before, just cover the pan with foil.
Make the picadillo. Turn the heat to medium-high under the same sauté pan. Only add oil if you don't think there's enough fat from the meat. Add the onions and garlic and cook until soft, about 5 minutes. Then add the almond meal or finely chopped almonds, plantains, tomatoes, capers, raisins, chipotles, cumin and the shredded, chopped steak. Stirring from time to time, cook everything together for about 10 minutes to fully combine all of then flavors, and season to taste with salt and pepper. (Here's How to Season to Taste.) Cool to room temperature.
Assemble. To assemble, place each ball of dough between two pieces of plastic wrap and flatten them with the palm of your hand. Now you can add a bit of the Picadillo to half of the rounds of dough, right in the center -- I use the same 1¼-inch scoop, filling it about ¾ of the way. Place a second flattened round of dough on top, and using another piece of plastic wrap, gently press it down, and use a fork to gently "seal" the edges."
Fry the empenadas. Generously coat a non-stick sauté pan with oil, and place it over medium-high heat. Once the pan is hot, add a few of the empenadas -- as many as you can fit, with a couple inches between them. You should hear a sizzling sound as they hit the pan, and if you don't, wait until the pan is hotter. Cook until the empanadas are golden brown, about 2 minutes per side (flip them carefully). Drain them on paper towels and serve!