In a wide skillet, heat a generous pour of olive oil then add the sliced peppers. Sauté over a lively flame until the peppers are almost tender and their skins have crinkled and have started to brown around the edges. Regulate the flame so the peppers don't brown too much.

If using, add the onion and red peppers a few minutes before the peppers are done.

Lower the heat a bit and add the potatoes. Give the potatoes a stir to cover them in the oil, the cover. Gently simmer until the potatoes are half cooked.

Uncover the skillet and raise the heat. Sauté the potatoes over a lively flame until they are almost fully tender and lightly browned.

Add the peppers and any accumulated juices back into the skillet. Turn to mix the potatoes and peppers together. Season to taste and let the peppers and potatoes simmer together until they are both perfectly tender. If you like, you can raise the heat at the end to get some caramelization on them.

Turn off the heat. Let the potato and peppers rest, covered, for at least 30 minutes before serving. Serve still slightly warm or, if you want to eat your pipi e patate hot, gently reheat before serving.