For the dough, put the water in a large pot over medium heat and add salt to taste.
Heat the water without letting it boil, then add the masarepa slowly, stirring with a wooden spoon, until you have a thick mixture. If it looks too dry, add a little more water. Take it off the heat and set aside.
Marinate the meat with the garlic.
For the hogao, cook the onions, garlic and red pepper in a pan. When the onion turns translucent, add the tomato, then season with salt, black pepper, saffron and cumin. Let it cook down until it is thick and jammy.
Meanwhile, cook the peas in water until soft, and prepare the carrots and potatoes: dice or slice them as you prefer.
Lay out the plantain leaves. Soften each one first over a flame or in boiling water until it darkens and turns pliable, and check none are torn or cracked along the folds.
Stir half the hogao through the dough. Spread a portion of dough on the leaves, then add the meats, vegetables and potatoes with a little more hogao on top. Repeat five more times.
Wrap using one leaf and then a second one over it, folds underneath, and tie firmly with twine.
Fill a large pot with water, bring it to a boil and salt it. Add the tamales and cook for 1 hour 30 minutes to 2 hours at a steady simmer.
If the water runs low, top it up with boiling water so the cooking does not stop.
Drain and serve hot. Open one to check: the masa should be firm and come away from the leaf cleanly.