This light, fresh-tasting soup is also delicious served chilled.
In a medium saucepan, heat oil over medium heat. Add shallots and saute for 2 minutes. Add potatoes and chicken stock; bring to a boil, then reduce heat and simmer for 15 minutes, or until potatoes are tender. Add frozen peas and snow peas; simmer for 3 more minutes, or until just tender and still bright green. Stir in mint leaves.
Remove pan from heat and allow to cool slightly. Puree in small batches in a blender or food processor until smooth. Return to saucepan and heat through. Season with salt and pepper, ladle into bowls, and sprinkle with croutons and pea shoots if desired.