Andalusia's cherished poor-man's potatoes: sliced potatoes slow-poached in olive oil with sweet green Italian peppers and onions until melt-in-the-mouth tender, finished with a dash of vinegar.
In a wide, deep skillet, layer the sliced potatoes, sliced peppers, onions, and garlic. Season generously with salt and pepper.
Pour the olive oil over the vegetables. Cover with a lid and cook over medium-low heat for 20-25 minutes, gently stirring once or twice, allowing potatoes to confit and soften in the oil without browning.
Remove lid, raise heat slightly for 5 minutes to lightly color edges. Splash in the white wine vinegar and toss gently so the steam balances the sweetness.
Tilt pan to drain excess oil (reserve for tortillas). Serve the sweet, silky potatoes warm as the ultimate Spanish meat or fish accompaniment.