Heat the olive oil in a large pot over medium heat.

Add the diced onion and cook for 4 to 5 minutes, stirring occasionally, until softened.

Add the garlic and cumin. Cook for 1 minute until fragrant.

Stir in the tomato paste until evenly combined with the onions and garlic.

Add the diced sweet potatoes, peanut butter, and vegetable broth.

Stir well until the peanut butter and tomato paste have completely dissolved into the broth.

Bring the stew to a boil.

Reduce the heat to a simmer and cook for 20 to 25 minutes, stirring occasionally, until the sweet potatoes are fork tender.

Stir in the collard greens and cook for an additional 5 minutes, or until wilted and tender.

Serve warm topped with fresh cilantro and rice if desired.