Add garlic, cumin, coriander, and smoked paprika; cook until fragrant, about 1 minute.
Add chicken pieces; season with salt and pepper. Cook until lightly browned on all sides, about 4–5 minutes.
Pour in chicken broth and diced tomatoes. Stir to combine.
Add cubed butternut squash. Bring soup to a boil, then reduce heat to low. Simmer, covered, until squash is tender and chicken is cooked through, about 15–20 minutes.
Stir in chopped kale or spinach; cook until wilted, about 2 minutes.
Adjust seasoning with salt, pepper, and red pepper flakes if using.
Serve hot, garnished with fresh parsley or cilantro.
Notes
Make it vegetarian: omit chicken and use vegetable broth; add chickpeas for protein.
Swap in sweet potatoes or parsnips for butternut squash.
Prep ahead: chop vegetables and store in fridge; cook soup when ready.
Freeze extra in airtight containers for up to 3 months.
Garnish options: a squeeze of lemon juice, a dollop of Greek yogurt, or grated Parmesan.