1. Place potatoes in a medium pot, cover with cold water, and bring to a boil over high heat. Lower heat to medium low and cook until potatoes are firm but slightly tender, about 7 minutes. Drain in a colander, run cold water over potatoes, and leave to cool for 10 minutes.
2. While potatoes cook, shell peas. You should have about 3/4 to 1 cup peas.
3. Prepare vinaigrette. Place oil, vinegar, mustard, garlic, salt, and pepper in a small bowl and mix until well combined.
4. Transfer potatoes to a serving bowl, add vinaigrette and gently mix until potatoes are coated with dressing. Add shelled peas, mint, and feta, and stir gently. Serve at room temperature or chilled. May be made 1 day in advance and stored, refrigerated, in an airtight container.
Source: Hannaford fresh Magazine, July - August 2009