Add oil to a large saucepan, turn the heat to medium and add the chopped carrots, celery and onion. Turn the heat down and sauté slowly till they have softened.
150 grams carrots, 100 grams celery, 1 medium red onion, 3 tablespoons olive oil
Add the potatoes and pour in the water, add salt, rosemary and tomato puree. Bring to a boil and lower the heat to gently simmer for 20 minutes, stirring occasionally.
Add the cavolo nero and the small pasta. Stir occasionally and cook till the pasta is done (see notes).
2 leaves cavolo nero, 100 grams pasta
Taste for seasoning, and add more salt if required. Garnish with basil leaves, freshly ground black pepper and grated parmesan cheese. Serve with rustic bread.
Use fresh seasonal vegetables for best flavour, and chop them to roughly the same size so they cook uniformly.
Use good quality canned beans with no hidden nasties which might compromise the flavour. I prefer to use the Cirio brand.
Partially mashing the beans and using the bean water adds extra creaminess to the soup.
*Any short variety of pasta can be used. This can be substituted with small pieces of rustic bread or carnaroli rice (cooking time- according to the instructions on packet).
For a low carb option - leave out the beans and the cereals.
Serve warm or at room temperature.
Make ahead - prepare the day before for best flavour and heat before serving, or serve at room temperature.
To store - bring to room temperature then transfer to an airtight container and keep in the fridge for 3-4 days, or in the freezer for up to 2 months and defrost in the fridge overnight.