Potato and Arugula Soup

Directions

1. 1
   In a large heavy pot, heat the oil over medium high heat until hot.
2. 2
   Stir in the onions, garlic, and 3/4 teaspoon salt and cook, stirring occasionally, until golden, 6 to 8 minutes.
3. 3
   Peel and dice the potatoes.
4. 4
   Stir in the stock and potatoes, then bring to a gentle boil.
5. 5
   Cook, stirring occasionally, until the potatoes are very soft and starting to fall apart, 45 minutes to 1 hour.
6. 6
   Stir in the arugula until just wilted, about 3 minutes, then season the soup with salt to taste and serve.