Open and drain the butter beans. Rinse under cold water.
Peel and roughly chop the onion. Peel the garlic.
Make the stock.
Heat the butter and oil in a large saucepan.
Fry the beans and onion for 5mins over a gently heat.
Pour in the stock, pop in the garlic cloves and allow to simmer for 15mins.
Remove from the heat – blitz for 5 mins on full power. This is essential to get a smooth, velvety texture soup. ( it can be passed through a sieve also)
Season as needed.
Stir in cream and allow to warm through.
To garnish: Pop the pancetta on greaseproof paper on an oven tray and bake at 180oC for 10mins until crisp. Chop up into small pieces. Top with grated mature cheddar, crispy pancetta ( bacon ) and freshly chopped chives.