Heat the butter over a medium heat in a large pan and add the spring onions. Sweat until cooked, but not coloured.
Place the pancetta in the oven to cook at 180°C for 10-15 minutes until crispy.
Add the peas and garlic to the spring onions, then pour in 750ml vegetable stock. Bring to the boil, then simmer for about ten minutes.
Puree the soup, season and add a dash of single cream.
Pour into shot glasses and top with a rasher of pancetta and small sprig of mint.