Dice the onion into ½-inch pieces, peel and cut the sweet potato into 1-inch chunks, mince the garlic cloves, and measure out all your spices (paprika, cumin, coriander, and chili powder) into a small bowl. Having everything prepped and ready ensures smooth cooking without interruptions. Heat the olive oil in a large pot over medium heat until it shimmers, then add the diced onion and cook for about 5 minutes, stirring occasionally, until softened and translucent.
Crumble the turkey sausage directly into the pot with the softened onion, breaking it into small pieces as it cooks. Let it brown for about 2-3 minutes, stirring occasionally to ensure even cooking. Add the sweet potato chunks and cook for another 3 minutes, allowing the sausage and potatoes to develop color and deepen the flavor base.
Add the minced garlic to the pot and cook for 2-3 minutes, stirring constantly to prevent burning—this releases the garlic's aromatic compounds and mellows its raw bite. I find that cooking garlic briefly with fat makes it taste much more integrated into the soup rather than sharp.
Pour the chicken broth into the pot, then add the measured spice mixture (paprika, cumin, coriander, and chili powder) from Step 1, along with salt and pepper to taste. Stir well to combine all the spices evenly throughout the liquid. Increase the heat to bring the soup to a boil, then reduce to a simmer, cover partially, and cook for 5-10 minutes until the sweet potato chunks are just tender when pierced with a fork.
While the soup is cooking, roughly chop the kale and rinse and drain the kidney beans to remove excess sodium. Once the sweet potatoes are tender, stir in the kale, beans, and fire-roasted diced tomatoes (with their liquid) and cook uncovered for about 5 minutes until the kale wilts and everything is heated through. I like using fire-roasted tomatoes because they add a subtle smokiness that complements the spices perfectly.
Give the soup a final stir and taste for seasoning, adjusting salt and pepper as needed. Ladle into bowls and serve warm. This soup tastes even better the next day as the flavors meld together, so don't hesitate to make it ahead.