In a small bowl or a jar fitted with a lid, combine the olive oil, lemon juice, mustard, and shallot. Season with salt and pepper. Set aside.
Cook the orzo according to the manufacturer’s instructions. Drain, then transfer to a large serving bowl. Add the dressing and toss to combine. Let the pasta cool to room temperature, tossing from time to time, about 20 minutes. (The pasta can be made in advance and refrigerated in an airtight container.) Just before serving, add the chicken, strawberries, walnuts, arugula, mint and red onion. Garnish with crumbled Saputo Feta cheese and serve.
