Slice new potatoes in half or quarters (depending on size) and place in a large pot.Cover with cold water and bring to a boil. Turn down the heat to a slow boil and cook for 12 to 15 minutes – until fork tender.
Trim green bean ends and cut green beans in half.
Snap off tough ends of asparagus and then slice asparagus into an equal size as the green bean pieces.
While potatoes are cooking, bring another pot of water to a boil. Once it’s boiling add both the green beans and asparagus to the boiling water. Cook for 4 to 5 minutes.
Prepare an ice bath (large bowl with half ice and half water). When the green beans and asparagus are ready – drain in a colander and then plunge into ice bath.Let them sit in the ice bath until completely cool.
Prepare vinaigrette by whisking together olive oil, red wine vinegar, dijon mustard,minced garlic and black pepper.
Mince red onion and set aside.
Mince the parsley and set aside.
Drain the potatoes when ready, add to a bowl, add half the vinaigrette to the warm potatoes and toss to coat the potatoes.
Drain the green beans and asparagus from the ice bath. Pat green beans and asparagus with paper towel so they are mostly dry.
Add green beans, asparagus, red onion, parsley and walnuts to potatoes. Toss with the remaining vinaigrette and serve