Heat the vegetable oil in a large pan or pot over medium heat. Add the chopped onion and sauté until translucent.
Add the diced green bell pepper and grated carrots to the pan. Cook for a few minutes until the vegetables start to soften
Stir in the chopped tomatoes, minced garlic, curry powder, paprika, cumin, coriander, chili flakes, salt, and pepper. Cook for another 2-3 minutes to allow the flavors to meld.
Add the canned baked beans, canned chopped tomatoes, tomato paste, vinegar, and sugar to the pot. Stir well to combine.
Reduce the heat to low and simmer the chakalaka for about 20-25 minutes, stirring occasionally. The vegetables should be tender and the flavors well blended.
While the chakalaka is simmering, prepare the vegetable atchar. In a separate bowl, combine the grated carrots and cabbage. In a small saucepan, heat the vinegar, sugar, salt, turmeric, mustard seeds, and chili flakes (if using) until the sugar dissolves. Pour the hot vinegar mixture over the grated vegetables and stir well. Allow the atchar to cool.
Once the chakalaka is cooked, remove it from the heat and let it cool slightly. Serve the chakalaka warm with a dollop of vegetable atchar on top. Garnish with fresh cilantro or parsley.