Place the top oven rack in the center position and pre-heat the oven to 400°F.
Pour the fish or chicken stock into a large sauce pan. Bring it to a light simmer over medium heat.
Meanwhile, put the prawns in a large bowl and drizzle with two tablespoons olive oil. Season with salt and black pepper, to taste, and toss to combine. Spread shrimp into an even layer on a rimmed baking sheet lined with parchment paper or a silicone baking mat. Set aside.
In a separate large skillet, heat the remaining olive oil over medium heat. Add the onion, celery, and garlic. Season with a pinch or two of salt and black pepper. Cook, stirring occasionally, until the onion becomes soft and translucent, approximately 4-5 minutes.
Add the arborio rice to the skillet and lightly toast, stirring continually, for about 1-2 minutes. Pour in the wine and stir continually until the wine is almost fully absorbed, approximately 2-3 minutes.
Add one half cup of the warm fish or chicken stock to the skillet and stir constantly until it is absorbed into the rice, approximately 2-3 minutes. Repeat with the remaining stock, stirring continually until the excess liquid is absorbed and the rice is cooked through, approximately 25-30 minutes total.
Add the peas to the risotto in the last 5 minutes of cooking and stir to combine.
Once the peas are added to the risotto, place the prepared prawns into the pre-heated oven and roast for 5-6 minutes, or until they are opaque. Do not overcook. Remove from oven and set aside.
When the peas are heated through, stir the fresh parsley, lemon zest, lemon juice, and grated cheese (if using) into the risotto until thoroughly combined. Serve immediately topped with the roasted prawns and fresh lemon wedges on the side.
Garnish with additional fresh parsley and grated cheese, if desired.