1 lb boneless skinless chicken breasts, cut into 1/2-inch cubes
1 medium yellow onion, finely diced
Kosher salt and pepper to taste
2 tablespoons unsalted butter
2 medium cloves garlic, minced
3 tablespoons all-purpose flour
1–1/2 cups 2% or skim milk
1/2 cup heavy whipping cream
2–1/2 cups chicken broth
1–1/2 lbs sweet potatoes, peeled and cut into 1/2-inch cubes
1 tablespoon minced fresh thyme
2 cups packed baby spinach or chopped kale
Crusty bread for serving (optional)
Instructions
Heat Dutch oven over medium-high heat. Add olive oil and swirl to coat. Add chicken and onion, season with salt and pepper, and sauté 5-7 minutes until chicken reaches 165°F internal temperature and onions are tender. Transfer to a plate and set aside.
Melt butter in same pot over medium heat. Add garlic and cook 1 minute until fragrant. Whisk in flour and cook 1-2 minutes until golden brown.
Slowly add milk in 6 additions (about 1/4 cup each), whisking constantly after each pour until smooth. Takes about 3-4 minutes total. Add heavy cream and chicken broth, whisking to combine.
Add sweet potatoes, thyme, and cooked chicken mixture. Bring to a simmer over medium-high heat with small bubbles forming around edges.
Reduce heat to medium-low and simmer 8-10 minutes until sweet potatoes pierce easily with fork but still hold shape.
Add spinach or kale and stir until wilted, about 1-2 minutes. Season with salt and pepper to taste. Serve warm with crusty bread.
Notes
Use boneless skinless chicken thighs instead of breasts for extra juicy, flavorful results.
Cut sweet potatoes into uniform 1/2-inch cubes so they cook evenly.
Keep soup at a low simmer to prevent dairy from separating. Do not boil.
Whisk constantly when adding milk in small increments to prevent lumps in the roux.
If soup is too thick, whisk in additional broth or milk 1/4 cup at a time.
Use a 5-quart or larger Dutch oven for best results.