Heat olive oil in a large Dutch oven or pot over medium heat. Add the sweet potatoes, onion, and celery and cook, stirring often, for 5 minutes.
2 tablespoons olive oil, 2 medium sweet potatoes, 1 medium onion, 4 ribs celery
Add the garlic, rosemary, thyme, salt, and pepper and cook for 30 seconds. Stir in the cannellini beans and broth.
3 cloves garlic, ½ teaspoon dried rosemary, ½ teaspoon dried thyme, ½ teaspoon salt, ⅛ teaspoon black pepper, 2 cans (15 ounces each) cannellini beans, 4 cups low sodium vegetable broth
Increase the heat to high and bring to a boil. Cover, reduce heat to a medium simmer, and cook until sweet potatoes are softened, about 8 minutes. Stir in the kale and cook until wilted, about 2 minutes. Serve.
1 medium bunch kale