Photo credit: G. Drakopoulos - Food Styling: T. Webb
- Place the baby potatoes in a medium pot. Cover them with water. Boil for 15 minutes or until they are soft enough to be easily pierced by a knife. Drain and allow to cool until they reach room temperature.
- To prepare the pickled onions, add the vinegar, water, salt and sugar in a jar with a lid. Cover and shake until the sugar and salt dissolve completely.
- Thinly slice the onions and add them to the mixture in the jar. Cover and refrigerate until needed. If possible, refrigerate overnight.
- Fill the same pot you used to boil the potatoes, with salted water and bring to a boil. Prepare a a large bowl full of water and ice cubes. Cut off the hard stems from the asparagus. As soon as the water comes to a boil, add the asparagus. Add the peas 1 minute later. Cook for 2 minutes and drain. Immediately put the vegetables in the ice water. Drain and spread them out on paper towels so they can strain any excess water.
- Chop the asparagus into 1 ½ cm pieces and put them in a large bowl. Chop the potatoes into medium sized cubes and add them to the bowl also. Thinly slice the radishes with a mandolin. If they are very big, you can slice them lengthwise, first.
- 1-2 hours before serving, whisk together all of the ingredients for the vinaigrette and drizzle over vegetables. Add as many pickled onions as you like. Season with salt and pepper and serve.