Preheat the oven to 375°F.
With a sharp knife, create a T cut along the face of the pepper for stuffing. To do so, cut the top rim of the pepper half way around, but do not cut the whole top of the pepper off. Then, cut down the middle of the body, along the flattest part or the face of the pepper. Cut almost to the tip. Gently pry the pepper open and pull out the seeds. Rinse if needed and set aside.
In a medium bowl, toss the cheese with the green onion, olives, pimentos, and lemon zest. Stuff the peppers with cheese mixture. Place the peppers on a baking sheet lined with parchment paper or foil. Bake for 45 minutes or until the peppers are blistered and the cheese is melted.
In a jar with a fitted lid, add the canola oil, vinegar, salt, and pepper and shake well to combine.
Drizzle the peppers with the dressing and serve.