In a medium saucepan, combine the chicken broth and water. Heat over low heat until warm.
In a large skillet, heat the olive oil over medium heat. Add the chopped onion and cook until translucent, about 5 minutes. Stir in the minced garlic and cook for an additional minute.
Add the Arborio rice to the skillet and stir for 2-3 minutes until the rice is lightly toasted.
Pour in the white wine (if using) and stir until it is mostly absorbed by the rice.
Begin adding the warm broth mixture, one ladle at a time, stirring frequently. Wait until the liquid is mostly absorbed before adding more. Continue this process for about 18-20 minutes, or until the rice is creamy and al dente.
Stir in the miso paste and soy sauce until well combined.
Add the flaked salmon and frozen peas, stirring gently to combine. Cook for an additional 2-3 minutes until heated through.
Remove from heat and stir in the grated Parmesan cheese. Season with salt and pepper to taste.
Serve the risotto warm, garnished with nori strips and chopped green onions.