Green Bean and Potato Salad

I have started to go to farmer's market regularly and am finding myself with some good stuff. The bean and potatoes used in this recipe are from the market.

Ingredients:

Green Beans - 1/2 lb, cleaned ends trimmed and cut into 1 to 2 inch pieces
Potatoes - 3 medium, peeled and cubed

For dressing:
Olive oil - 1/4 cup
Lemon Juice - 1/8 cup
Ground Mustard - 2 Tbsp.
Slat and fresh pepper to taste

Procedure:
- Bring 1 quart of water to boil. Salt the water.
- Add green beans and cook for 2 to 3 minutes till the beans are cooked just enough.
- Remove from water and pat try on kitchen towels.
- Add potatoes to the hot water and cook them . DO not over cook so potatoes get all mushy.
- Mix all the ingredients for dressing and whisk them or just run it through a food processor. Adjust seasoning.
- Mix beans and potatoes in a salad bowl and add the dressing.