Bring a large pot of salty water to a boil and cook orzo according to package instructions. When you have 2 minutes of cooking time remaining, add the peas to the pot. Strain peas and pasta and set aside.
At the bottom of a large mixing bowl, whisk together the Yogurt-Dill Vinaigrette: yogurt through olive oil.
Add orzo, peas, carrots and onion to the bowl with the vinaigrette and toss well to combine. Check for seasoning and adjust accordingly.
Dish can be made up to 3 days in advance if kept in an air-tight container in the refrigerator. Over time, the pasta will absorb a bit of the vinaigrette so feel free to drizzle with a little extra olive oil or lemon juice or add a bit of salt if needed before serving.