Chop sweet potato, and put in microwave until soft (about 5 minutes). Make sure to use a microwave safe bowl, and you may want to add 1-2 table spoons of water to steam cook them.
While the sweet potato is cooking, heat olive oil in a large pot over medium heat. Toss in the diced chicken and garam masala, stirring to coat the chicken. Cook for about 3-4 minutes until the chicken begins to brown.
Add the sliced onion, garlic, ginger, and chopped cilantro stems to the pot. Sauté until the onion softens —about 3-5 minutes.
Toss in the microwaved sweet potato and the chickpeas. Stir everything together before pouring in the bottle of butter chicken sauce and the chicken stock.
Bring the soup to a boil, then reduce the heat to medium and let it simmer for about 5 minutes.
Stir in the spinach, fresh cilantro, and a squeeze of lime juice. Give it a taste and adjust the salt if needed.
