In a large Dutch oven or heavy-bottomed pot over medium heat, warm the olive oil until shimmering. Add the chopped onion, bell pepper, carrot, celery and ¼ teaspoon salt. Stir to combine and then cook, stirring occasionally, until the vegetables are tender and the onion is translucent, about 7 to 10 minutes.
Add the garlic, chili powder, cumin, smoked paprika (go easy on the paprika if you’re sensitive to spice) and oregano. Cook until fragrant while stirring constantly, about 1 minute.
Add the diced tomatoes and their juices, the drained black beans and pinto beans, vegetable broth and bay leaf. Stir to combine and let the mixture come to a simmer. Continue cooking, stirring occasionally and reducing heat as necessary to maintain a gentle simmer, for 30 minutes. Remove the chili from heat.
For the best texture and flavor, transfer 1 ½ cups of the chili to a blender and blend until smooth, then pour the blended mixture back into the pot. (Or, you can blend the chili briefly with an immersion blender, or mash the chili with a potato masher until it reaches a thicker, more chili-like consistency.)
Add the chopped cilantro, stir to blend, and then mix in the vinegar, to taste. Add salt to taste, too—I added ¼ teaspoon more at this point. Divide the mixture into individual bowls and serve with garnishes of your choice. This chili will keep well in the refrigerator for about 4 days (I haven’t tried, but I bet it would freeze well, too).