Place the pancetta cubes in a large, cold skillet in a single layer. Set the heat to medium-low and cook for 8 to 10 minutes, stirring occasionally, until the fat has melted into the pan and the cubes look pale gold and feel firm when pressed with a spoon.

Transfer the pancetta with a slotted spoon to a paper towel-lined plate. Spread it out and let it rest while you cook the peppers.

Pour off all but 1 tablespoon of the rendered fat. Raise the heat to medium-high and add the peppers and onion. Cook for 6 to 7 minutes, stirring only every minute or so, until the edges are charred in spots and the peppers are crisp-tender.

Push the peppers to one side and return the pancetta to the empty half of the pan. Cook over medium-high heat for 2 to 3 minutes, turning often, until the cubes are deep amber and you can hear a steady crackle.

Add the garlic and smoked paprika and stir everything together for 30 seconds, until fragrant. Take care that the garlic does not turn brown.

Remove the pan from the heat and splash in the vinegar, tossing to coat. Season with black pepper, taste, and add salt only if needed.

Transfer to a serving dish and scatter with parsley. Serve right away, while the pancetta is still crisp.