Combine the lemon, parsley, garlic, oil and salt in a blender until mostly smooth.
Toss the chicken with the gremolata and marinate overnight or for at least 4 hours.
Preheat the oven to 400°F.
Remove the chicken from the marinade, discard marinade and season chicken with salt and pepper. Roast on a baking sheet until cooked through, about 18-22 minutes.
On a baking sheet, toss the potatoes and onions with 2 tablespoons oil, salt and pepper. Roast for 15 minutes, or until crisp. Toss with parsley after removing from the oven.
On a separate baking sheet, toss the artichoke hearts with the remaining oil and roast for 10-15 minutes, or until crisp.
Boil a large pot of salted water for the green beans. Prepare an ice bath by filling a large bowl with cold water and ice. When the water boils, add the green beans for 2 to 4 minutes, until bright green. then immediately transfer to the ice bath to stop the cooking process. Remove from the ice bath after 1 to 2 minutes.
Toss the green beans with the potatoes, onions and artichokes in a serving bowl.
Add all of the vinaigrette ingredients to a blender and purée until smooth, adding water if necessary to reach desired consistency. Adjust seasoning with salt and pepper.
To serve, divide the hash between plates, top with chicken and drizzle with basil vinaigrette.