In a jar or bowl, mix the sliced onion, habanero, vinegar, water, and salt.
Stir well and let it marinate at room temperature for at least 30 minutes, ideally 1 hour, until the onion is pickled and softened.
The key to authentic Panades is the correct corn dough (Masa) enriched with Red Recado (Achiote) to give it its yellowish color. They are thin, crispy, and quickly fried.
The essential component is the spicy and acidic onion sauce, Curtido, which cuts through the richness of the fried food.
In a jar or bowl, mix the sliced onion, habanero, vinegar, water, and salt.
Stir well and let it marinate at room temperature for at least 30 minutes, ideally 1 hour, until the onion is pickled and softened.
Boil or sear the fish with a little oil until cooked. Use a fork to flake it into small pieces.
In a skillet, sauté the onion and garlic in a little oil until softened. Add the flaked fish, Red Recado (Achiote), salt, pepper, and thyme.
Heat through for 5 minutes. The filling should be dry so it doesn't soak the dough. Set it aside and let it cool.
In a large bowl, mix the Masa Harina, salt, and Red Recado (if using paste dissolved in water, add it now).
Gradually add the warm water and knead until a soft but non-sticky dough is formed. It should have a playdough-like consistency. If dry, add more water; if too wet, add more Masa Harina.
Cover and let it rest for 15 minutes.
Divide the dough into balls about 3 cm (golf ball size) in diameter.
Press each ball into a thin disk using a tortilla press (between two pieces of plastic) or roll it out between two sheets of plastic to tortilla thickness.
Place about 1 tsp of the fish filling on one half of the disk. Fold the disk over in half to form a crescent shape (like an empanada).
Firmly pinch the edges together with your fingers or a fork to seal the dough and prevent the filling from escaping during frying. Set them aside on a paper-lined tray.
Heat the oil in a deep pot to a temperature of 185 °C (365 °F).
Fry the Panades in small batches (3-4 at a time) for about 3-4 minutes until they are puffy, crispy, and golden-orange. They should float when cooked.
Remove them with a slotted spoon and drain on paper towels.
Serve the Panades immediately, hot. Drench each serving generously with the spicy pickled onion sauce, Curtido.