In a large saucepan, heat the olive oil over medium heat. Add the chopped onion and sauté until translucent, about 5 minutes. Stir in the minced garlic and cook for an additional minute until fragrant.
Add the Arborio rice to the saucepan and stir for 2-3 minutes, allowing the rice to toast slightly and absorb the flavors.
Gradually add the chicken broth, one cup at a time, stirring frequently. Wait until the liquid is mostly absorbed before adding the next cup. This process should take about 18-20 minutes.
When the rice is creamy and al dente, stir in the shredded chicken and frozen peas. Cook for an additional 3-5 minutes until the peas are heated through.
Remove the saucepan from heat and stir in the grated Parmesan cheese and heavy cream. Season with salt and pepper to taste.
Serve immediately, garnished with fresh parsley.