Cook brown rice according to package instructions. Set aside.
In a large pot, heat olive oil over medium heat. Sauté onions and garlic until fragrant.
Add carrots and cook for 5 minutes, stirring occasionally.
Stir in diced tomatoes, vegetable broth, cumin, salt, and pepper. Bring to a simmer.
Add kale, spinach, and collard greens. Simmer for 15–20 minutes until vegetables are tender.
Serve the stew hot over brown rice and garnish with fresh parsley.