Add olive oil to a pan over a low-medium flame and let it warm up.
Add in the onion and saute, constantly stirring, for about 22 to 25 minutes, until onions are caramelized.
Add in the garlic, carrots, celery, red bell pepper, mango, fire roasted tomatoes, cumin, coriander, smoked paprika, vegetable stock, tomato paste, apple cider vinegar, kidney beans and black beans . Cover the pan and let simmer for about 15 minutes.
Uncover the pan, season with salt and black pepper to taste.