Aromatics: warm the olive oil in a large dutch oven or heavy-bottomed pan over medium-high heat. Add the onion and sauté for 3 minutes, stirring occasionally. Add the carrots and celery and sauté for an additional 3 to 5 minutes. Then, add the garlic, thyme, paprika, cumin, coriander, and pepper. Mix the dry spices into the veggies and sauté for an additional 60 to 90 seconds.
Simmer: add the beans and vegetable broth to the pot and mix well. Increase the heat to high and bring the mixture to a boil, then reduce the heat to medium and simmer for 20 to 25 minutes, stirring the stew every 5 minutes or so to prevent anything from sticking to the bottom of the pot. You may need to reduce the heat to medium-low towards the end of cooking to prevent the stew from splattering.
Finishing Touches: Turn the heat off and stir in the parsley, lemon juice, and lemon zest (if using). Let the soup sit for 5 or so minutes, to allow the stew to cool and thicken.
Serve & Store: serve warm, and as desired. Store leftovers in the refrigerator for up to 5 days, or in the freezer for up to 2 months.