Heat the olive oil in a large heavy-bottomed pot over medium heat.
Add the chopped carrots, celery, and potatoes, and sauté for 5 to 7 minutes until they begin to soften.
Stir in the minced garlic and ground cumin, cooking for an additional minute until highly fragrant.
Add the drained fava beans, diced tomatoes, and vegetable broth to the pot, stirring well to combine.
Bring the mixture to a gentle boil, then reduce the heat to low, cover, and simmer for 25 minutes or until the vegetables are completely tender.
Lightly mash some of the beans and potatoes against the side of the pot with the back of a spoon to thicken the stew naturally.
Remove from heat, stir in the fresh chopped parsley, and serve warm.