Heat the olive oil in a frying pan over low heat. Add the finely chopped onion and cook for about 5 minutes, stirring occasionally until the onion is soft and translucent.

Cook the bacon until crispy using your preferred method: in a pan without oil, in an air fryer (8 minutes at 360°F), or in the oven. Once cooled, crumble the bacon into small pieces.

In a large mixing bowl, combine the drained kidney beans, cooked onions, and crumbled bacon.

Add the tomato puree, brown sugar, garlic paste, apple cider vinegar, Dijon mustard, and Worcestershire sauce to the bowl.

Season with salt, paprika, and black pepper, then stir everything together until well combined.

Transfer the bean mixture to your slow cooker. If the mixture seems too thick, add a little more tomato puree until you reach your desired consistency.

Cover the slow cooker with its lid and set it to cook on High for 3 hours.

After 3 hours, the baked beans are ready to serve. They can be enjoyed on their own, with toast, or garnished with fresh herbs.