This one is a little tricky to fit in the pot. Have two Trangias going if you're 4 persons and start by frying the veggies in a frying pan.
Add oil to frying pan. Add the chopped onion, bell pepper, carrot, celery and ¼ teaspoon of the salt. Stir to combine and cook, stirring occasionally, until the vegetables are tender and the onion is translucent, about 7 to 10 minutes.
Add the garlic, chili powder, cayenne, cumin, paprika and oregano. Cook until fragrant while stirring constantly, about 1 minute. Divide into two pots (or tarnsfer to one pot if you're cooking for 2 persons).
Add the diced tomatoes and their juices, the drained black beans and kidney beans, vegetable broth, bay leaf, sugar and worcestershire sauce (not strictly vegetarian). 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 the heat. Mash some of the beans up with a fork so you get a thicker consistency.
Add the vinegar, to taste. Add salt to taste and maybe some hot sauce if you want it spicier. Divide into bowls and serve with garnishes of your choice, tortilla ships ans squeezed lime. If you have some left-over it's great in an egg burrito in the morning.