Place peanuts in a food processor and pulse to roughly chop. A knife can also be used to smash or chop the peanuts.
In a large saucepan, heat oil over medium heat. Once heated, stir in the onion, ginger, and garlic. Cook, stirring occasionally, until the onion softens and becomes translucent, 3-5 minutes.
Chop the chicken into bite size pieces and add to the pan. Cook just until the chicken turns golden on the outside. Stir in 1/2 cup of the peanuts, pinch cayenne, salt, and pepper.
Add the chicken stock and sweet potatoes. Increase heat to bring to boil, then decrease heat to medium low. Stir in tomatoes and collard greens. Simmer, stirring occasionally, until the chicken is cooked through, sweet potato slices are soft, and tomatoes begin to break apart, 10-15 minutes. Stir in 1/4 cup peanut butter and slowly add more according to taste.
Garnish with remaining peanuts and serve immediately with rice.