Peel and finely dice onions and garlic. Heat the oil in a saucepan and sauté the onions and garlic until translucent. Turn the heat down a little. Add the peas and sauté lightly. Pour in the milk and season with broth. Simmer for a few minutes until the peas are quite soft. Chop the mint and stir in.
Puree with a hand blender to the desired consistency. Finally season with salt and pepper