Smoky Black Bean and Sweet Potato Soup with Lime

Wash the sweet potatoes and pepper. Peel the sweet potatoes and cut them into even 1.5 cm cubes. Dice the onion and seeded pepper, and chop the garlic. Drain and rinse the ready-cooked black beans; keep them separate until the sweet potatoes are nearly tender.

Warm the olive oil in a large heavy pot over medium heat. Add the onion and red pepper. Cook, stirring occasionally, for 6 to 8 minutes, until softened. Add the garlic, smoked paprika, cumin and mild chili powder; stir for about 1 minute until fragrant, without letting the spices scorch.

Add the sweet potato cubes, diced tomatoes and their juices, vegetable broth and measured salt. Stir, bring to a boil, then lower the heat to a gentle simmer. Partly cover and cook for 15 to 20 minutes, stirring occasionally, until a sweet potato cube is almost tender when pierced with a fork.

Stir in the drained black beans and simmer uncovered for another 5 minutes, until the beans are hot and the sweet potatoes are fully tender but still hold their shape. If the soup is thicker than you like, add a little water and return it to a simmer. Taste before adding any more salt.

Turn off the heat and stir in the 2 tablespoons lime juice. Divide into six bowls. Add the optional cilantro and offer lime wedges so each person can brighten their bowl to taste.

For leftovers, transfer the soup to shallow containers and refrigerate promptly, within 2 hours. Use within 2 to 3 days or freeze for later use. Thaw frozen soup in the refrigerator. Reheat soup to a full rolling boil while stirring, and check that it reaches 74°C (165°F) with a food thermometer; discard any reheated portion that is not eaten.