For the sweet potato cakes:
Adapted from Plenty by Yotam Ottolenghi
(Makes 34 small cakes)
2 pounds sweet potatoes, peeled and chopped into large chunks
½ cup all-purpose flour
1 teaspoon salt
½ teaspoon freshly ground black pepper
5 green onions, both white and green parts, finely chopped
4-6 tablespoons extra virgin olive oil
4-6 tablespoons butter

For the black bean salsa:
1 16 oz. can black beans, rinsed and drained
1-2 chipotles in adobo, finely chopped
1 small, yellow bell pepper, small diced
¼ cup finely minced red onion
¼ cup cilantro leaves, chopped
Juice of 1 lime
¼ teaspoon salt

To assemble for serving:
½ cup sour cream