1. Heat the olive oil in a large pan over medium heat. Add the onion and garlic, and cook until softened.
2. Add the Arborio rice and stir to coat with the oil. Cook for 2-3 minutes until the rice is slightly translucent.
3. Pour in the white wine and cook until it has evaporated.
4. Gradually add the warm broth, one ladle at a time, stirring constantly until the liquid is absorbed before adding more. Continue until the rice is creamy and cooked through.
5. Stir in the mixed seafood and cook until the seafood is just cooked through.
6. Add the lemon zest, juice, and Parmesan cheese. Season with salt and pepper to taste.
7. Garnish with fresh parsley and serve immediately.