Heat 1 tablespoon of the olive oil and the pearl couscous in a saucepan over medium heat for about 5 minutes.
Add the water and ½ teaspoon of salt.
Increase the heat and bring to a boil.
Once the couscous is tender, drain it and spread it onto a baking sheet to cool completely, about 15 minutes.
In a bowl, whisk together the apple cider vinegar, Dijon mustard, paprika, sugar, the remaining 3 tablespoons of olive oil, and ⅛ teaspoon of salt.
Add the cooled couscous, arugula, green onions, radishes, parsley, and walnuts. Toss to combine.
Season with salt and pepper.
Add the goat cheese.
Serve.
