Heat the oil in a pot over medium heat. Add the garlic, onion, carrot and bell pepper and cook, stirring, 3-4 minutes. Mix in the spices, mint and flour and cook 1-2 minutes more. Slowly pour in the stock, stirring constantly. Add the potatoes and chick peas and bring to a gentle simmer and cook 15-20 minutes, until the potatoes are tender. Adjust seasoning and serve, if desired, on couscous.