Sauté the chopped, red onion in a medium sized saucepan with a lid for about 1-2 minutes. You can sauté in a dash of oil or water if you prefer to make the recipe oil free.
Add the garlic to the onions and stir through, before adding the frozen peas and vegetable stock. Bring to the boil quickly then leave to simmer for 4 minutes.
Remove the pan from the heat and add the parsley. Use a stick blender to blend the soup to your desired consistency.