Start by gathering all your ingredients. Chop the onion and mince the garlic. Cut the salmon into bite-sized pieces for even cooking.
In a large pot or Dutch oven, heat the olive oil over medium heat. Add the diced onion and sauté for about 3-4 minutes, until it becomes translucent. Then, stir in the minced garlic and cook for another 1-2 minutes until fragrant.
Pour in the can of diced tomatoes (with juices) and the chicken broth. Stir well to combine, ensuring the onion and garlic are evenly distributed.
Add the whole wheat orzo to the pot, along with the salt, pepper, and Italian seasoning. Stir everything together, making sure the orzo is submerged in the liquid.
Bring the mixture to a gentle boil, then reduce the heat to a simmer. Cover the pot and cook for about 10-12 minutes, stirring occasionally, until the orzo is tender and has absorbed most of the liquid.
Gently fold in the salmon pieces, nestling them into the orzo. Cover the pot again and cook for an additional 5-7 minutes, or until the salmon is cooked through and flakes easily with a fork.
Once the salmon is cooked, remove the pot from heat. Stir in the shredded Parmesan cheese until it melts and creates a creamy texture. Finish by sprinkling chopped parsley over the top for a fresh burst of flavor.