Caldo Verde

In a large heavy pot, heat the oil over medium high heat until hot. Brown the sausage, turning once, until golden, about 5 minutes. Transfer the sausage to a plate. Add the onion and garlic to the pot and cook, stirring until golden, about 6 minutes. Add the sausage back to the pot and stir in the stock, potatoes, and collards. Boil the soup until the potatoes are falling apart and the collards are tender, about 40 minutes. Season with salt and pepper to taste and serve.