Prep ingredients: Make sure arugula, potatoes and beans are all clean and dried. Boil water in medium saucepan over high heat. Add in potatoes and let cook for 15-20 minutes or until fully cooked. ( I like to check with a fork!) The smaller ones will cook quicker, larger ones will take a bit longer.
In the meantime, prepare sauce. Whisk together basil pesto, vinegar and oil. Taste for seasonings and if necessary season with salt and pepper. Set aside.
Boil 2 cups of water in a smaller pot. Ensure that the pot will hold the string beans. Once boiled, toss in string beans and cook for 3-4 minutes until crisp and tender. Immediately remove, drain and let sit in an ice bath for an additional 2-3 minutes. This will ensure the beans don't overcook. Drain again and set aside.
Remove potatoes from heat once cooked. Drain and let cool for 15 to 20 minutes. Place in a large bowl with string beans. Cover with dressing and toss to coat.
Plate arugula on a large platter. Top with Potato Bean mixture. Gently top with cut up hardboiled eggs. Serve and enjoy!