Melt the butter in a small saucepan over a medium heat and sizzle the shallot for 5 mins until soft. Add the stock and peas, and bring to a simmer. Cook gently for 10 mins until the peas are soft.

Roughly mash the pea mixture with a potato masher, or, if you prefer a smoother texture, purée with a hand blender. (It’s best to leave some of the peas whole or roughly crushed for texture.) Season to taste and stir through the mint leaves just before serving.