- 8 medium-large boiling potatoes (about 3 1/4 pounds)
- 1 cucumber
- 3 celery ribs
- 1 green bell pepper
- 1 small bunch radishes (about 8)
- 1 cup mayonnaise
- 2 tablespoons yellow (ballpark) mustard
- In a 5-quart kettle cover potatoes with salted cold water by 2 inches and simmer until just tender, 30 to 35 minutes. Drain potatoes in a colander and cool completely. Peel potatoes and cut into 3/4-inch pieces. Transfer potatoes to a large bowl.
- Peel and seed cucumber and cut cucumber, celery, and bell pepper into 1/4-inch dice. Thinly slice radishes and add with diced vegetables to potatoes, tossing gently. In a small bowl whisk together mayonnaise and mustard and drizzle over salad. Gently toss salad until combined well and season with salt and pepper. Salad may be made 1 day ahead and chilled, covered. Serve salad chilled or at cool room temperature.