Prep: 1. Boil 1 quart water in medium pan. 2. Cut potatoes, leek, mint, and chives. 3. Shell peas if using fresh ones. Make: 1. Add the potatoes and a pinch of salt to boiling water; cook over medium-high heat for 15 minutes or until tender. Add in peas and salt and boil for 5 more minutes. (when done, drain, reserving 1/2 cup of the liquid) 2. Meanwhile, in a large pan, heat the olive oil; add the leek and cook over low heat for 5 minutes. 3. Add the peas, the potatoes and the 1/2 reserved cooking water to the pan; simmer over moderate heat, stirring. 7. Add the mint, chives and 1 teaspoon lemon juice; season with salt and pepper. 8. Remove skillet from heat and stir in the arugula.
If you can't find fresh peas, or if you don't want to shell them, frozen peas work just fine. Leeks can be particularly dirty, make sure to rinse them thoroughly - https://www.youtube.com/watch?v=SdX6W6qpoEk