Season chicken all over with cumin and salt. Heat oil in a large pot over medium-high heat. Add chicken; cook for 3 to 4 minutes.
Flip; cook for an additional 3 to 4 minutes, or until browned on all sides. Remove from pot. Add onion and bell peppers to pot; cook, stirring occasionally, for 5 to 7 minutes, or until soft.
While onion and peppers cook, add 1 cup
broth, peanut butter, garlic, ginger, and chile to a blender; cover.
Pulse until smooth, scraping down sides as needed.
Return chicken to pot; add collard greens, remaining 3 cups broth, broth mixture, tomatoes, and sweet potato.
Bring to a boil; reduce heat to low.
Gently boil, uncovered, for 25 to 30 minutes, or until sweet potato is soft and soup thickens.
Remove chicken from pot; shred using two forks.
Return to pot.
Evenly divide soup among 4 serving bowls; top evenly with peanuts and mint.
Serve with a lime wedge.