One of the first memories I have of my mother cooking is her preparing piononos, a snack she'd make when she was feeling creative. Now, my mom wasn’t the kind of Puerto Rican mother who spent all day in the kitchen or passed down the recipes she learned from her abuela. She was a nurse and barely had time to cook. But when she did, her natural Puerto Rican superpowers kicked in, and bam! We'd have piononos. This classic Puerto Rican snack is made with ripe plantains fried and topped with picadillo (sweet-and-savory beef). It's very popular at weddings or family events as a bite-size appetizer.
For the picadillo: Heat the oil in a large skillet over medium heat. Add the onions and garlic and cook, stirring frequently with a wooden spoon, until the onions are translucent, 1 to 2 minutes. Add the ground beef and break up the meat with a wooden spoon. Stir in the tomato paste, adobo, sazón and tomato sauce until combined. Season with salt and pepper and cook, continuing to break up the meat until it is browned, 7 to 8 minutes.
Finally, add the cilantro and adjust the seasoning if necessary. Transfer to a large bowl and set aside.
For the plantains: Pour 1 inch of oil into a large saute pan or deep large skillet and place over medium-high heat. Line a plate with paper towels.
Using a sharp knife, trim off both ends of a plantain. Slit a thin line down the plantain, cutting just through the skin, and peel back the skin to remove it. Repeat with the remaining plantains. Slice each plantain lengthwise into 5 to 6 strips.
Fry the plantains 2 or 3 strips at a time until golden brown on both sides, about 5 minutes.
Transfer to the paper towel-lined plate to drain. Repeat with the remaining strips.
Preheat the oven to 400 degrees F. Grease the cups of a 12-cup muffin pan. Line the sides of the muffin cups with the longer plantain strips, then use trimmed pieces to cover the bottoms of the muffin cups.
Spoon the picadillo into the plantain-lined muffin cups, filling each about three-quarters full. Top each with a spoonful of the beaten eggs to help them hold together.
Bake until lightly browned, about 15 minutes. Use a knife to loosen the edges before removing the piononos from the muffin cups. Serve hot or warm.