Warm the olive oil on medium heat, in a large pot. Add the chopped onion, carrot, celery, bell pepper, and salt. Cook for 8-10 minutes, stirring occasionally. The vegetables will be tender and the onion will be translucent.
Add in the garlic, cumin, oregano, chili powder, and paprika. Stir for about a minute.
Add the diced tomatoes (inducing their juices), drained beans, broth (or water), and bay leaf. Stir for a minute and let it simmer. Cook for about 30 minutes, stirring occasionally. Reduce heat if needed to maintain a soft simmer.
Remove the chili from heat and remove bay leaf. For creamier chili, use a potato masher to mash up some of the chili. This will give you a thicker consistency.
Add chopped cilantro and lemon juice if desired and salt to taste. Serve and garnish with cilantro or vegan sour cream. You can store in the fridge for about 5 days or in the freezer for longer.