Heat olive oil in large kettle over medium heat. Add onions, salt, and pepper, and cook 5 minutes until onions have softened. Sir in the garlic and cook 1 minute until its aroma is released. Add the potatoes and saute 5 minutes until they begin to color. Add the chicken stock, lower the heat, and simmer gently 25 minutes until potatoes are soft. Add the peas and cook 3 minutes until tender but still bright green. Puree the mixture either through a food mill, with an immersion blender, or in a food processor, until smooth. Place in a clean pot, stir in the cream, and rewarm gently. Stir in the fresh mint and serve.

In Portugal, this soup is often made with fresh fava beans. Use them if you can find them. Mint (horteln) grows abundantly in Portugal and is widely used in savory dishes, frequently in combination with coriander (coentro).