Put the potatoes in pot with the garlic cloves.
Cover with cold water, add salt and bring to a boil.
Add the bread, cut or broken into pieces that easily fit onto a spoon.
Tear the arugula in half and toss into pot with the chile.
Simmer 10 minutes undisturbed. Poor in a slug of oil, and allow to sit for a few minutes to amalgamate.
Spoon into warm bowls, doused with more olive oil.