To a large bowl, add the ground chicken, 1/2 tsp salt, garlic powder, cumin, paprika, and black pepper. Mix to incorporate. Divide into 12-16 meatballs and roll between your palms until round.
Add a tablespoon of olive oil to a nonstick pot or skillet and place it over medium-high heat. Cook as many sides of the meatballs as possible until golden. The meatballs will not be fully cooked through, they will finish off cooking in the stew.
While the chicken meatballs are cooking, prep the other components. Dice the onion and carrot, mince the garlic, and roughly chop the collard greens. Once the chicken meatballs are golden on all sides, transfer them to a plate. Add a tablespoon of olive oil to the same pot and drop the heat to medium low.
Add the onion, carrots, and garlic and sauté for 3-4 minutes until fragrant. Add the chicken stock and tomato paste and bring to a boil. Drop the heat and let simmer for 5-7 minutes until thickened.
Drop the chicken meatballs in the stew and let simmer for 5-7 minutes until cooked all the way through. Add the collard greens and allow to simmer for 1-2 more minutes until slightly wilted. Season with salt and pepper to your preference. Stir in the lemon juice, and serve!