Heat 1 tablespoon vegetable oil in a large pan over medium heat.
Add the diced 1 medium yellow onion and sauté, stirring occasionally, until tender and translucent (about 4–6 minutes).
Add 40 g peas and cook 1–2 minutes until warmed.
Add 450 g mixed seafood and the tomato sauce to the pan, stir to combine, and cook on medium heat for 3–4 minutes until the seafood is heated through.
In a small bowl or measuring cup, stir together 250 ml water, 1 teaspoon saffron, and 1 teaspoon smoked paprika. Pour this mixture into the pan.
Bring to a simmer and cook until the liquid has reduced slightly, about 3–5 minutes.
Warm the 450 g cooked rice in the microwave until heated through (cover the bowl to retain moisture).
Add the warmed cooked rice to the pan, stir to combine, and simmer gently for 5 minutes so the flavors meld.
If using, add thin slices of red bell pepper in the last minute of cooking.
Taste and season with salt to taste. Remove from heat.
Garnish with chopped fresh parsley and serve with lemon wedges.