To a large bowl add the beans, cover with water, more than double the amount and soak at room temperature for 8 hours.

After 8 hours drain, discard the liquid and rinse the beans.

Add the beans to a large saucepan. Cover the beans about 2 inches (5 cm) above the beans with water and bring to a boil. Simmer for 1 hour uncovered. Stirring often so they don't stick to the bottom. Cooking time will depend on your beans so check them often for tenderness. Drain. If using already cooked beans, skip these 2 steps.

Preheat oven to 350°F/180°C.

To the same pan, add the ketchup (taste the ketchup for sweetness, you may need to adjust the amount of sugar so the sauce is not too sweet), tomato paste, sugar, garlic powder, onion powder, salt, vinegar and stock. Whisk to combine. In a small bowl, mix 1 tablespoon of stock or water with the cornstarch and mix until dissolved, stir into the sauce. Add the cooked beans and stir well.

Transfer the beans and sauce to a high-sided baking dish, or, if your pan is ovenproof use that and transfer to the oven, Bake uncovered until thickened, 20-25 minutes.

After soaking and rinsing the beans, turn your slow cooker on low. Add all the ingredients EXCEPT THE SALT, as this can cause the beans to take longer to cook. Put on the lid and cook for 6 to 8 hours, but start checking them at the 6th hour for tenderness, then stir in the salt.