Step 1

Place beans into a large bowl. Cover with plenty of cold water. Set aside for 6 to 8 hours to soak.

Step 2

Heat oil in a large saucepan over medium heat. Add leek and garlic. Cook, stirring often, for 6 to 7 minutes or until soft. Drain beans. Rinse well. Add to saucepan with stock, water and tomatoes. Increase heat to high and bring to the boil. Reduce heat to medium. Simmer, partially covered, for 20 minutes.

Step 3

Add zucchini, carrots, celery and chorizo to saucepan. Simmer, partially covered, for a further 20 minutes. Use tongs to remove chorizo from soup. Set aside to cool slightly. Add silverbeet to saucepan. Remove from heat.

Step 4

Chop chorizo and return to soup. Taste and season with salt and pepper. Ladle into bowls. Serve. Shortcut - Place beans into a 12-cup capacity microwave-safe bowl with 2 1/2 cups cold water (beans should be covered with water). Cover with a lid or double layer of plastic wrap. Cook for 5 minutes on HIGH (100%) power, followed by 30 minutes on MEDIUM-LOW/DEFROST (30%) power. Drain. Rinse again and drain.