Heat olive oil in a large Dutch oven pot over medium heat.
Add Italian sausage and cook for about 4-5 minutes, breaking its up with a wooden spatula into small crumbles.
Add diced onion to the pot and continue cooking until onion is soft, about 5 minutes.
Add salt, pepper, red pepper flakes and garlic to the pan. Stir to combine and cook until garlic is fragrant, about 1 minute.
Add Orzo pasta and stir to combine with the seasoned sausage.
Add 2 cups chicken broth, stir to combine.
Add heavy cream and stir to combine.
Bring mixture to a simmer. Reduce heat and cook on low heat for 10 minutes.
Stir occasionally to prevent pasta from sticking to the bottom of the pan.
Stir in reserved ¼ cup of chicken stock to thin the sauce.
When pasta is cooked al dente turn off heat and add the parmesan cheese to the pan. Stir to combine.
Add frozen peas and stir to combine.
Cover pan with a lid and allow risotto to rest for 5 minutes.
Serve topped with shaved Parmesan cheese if desired.