Heat the extra virgin olive oil in a wide skillet or paella pan over medium heat.
Add the diced onion and red bell pepper, sautéing until the vegetables are softened and translucent.
Stir in the minced garlic and smoked paprika, cooking for 30 seconds until fragrant.
Add the tomato puree and cook for 2 minutes, stirring constantly to create a concentrated base.
Add the Bomba rice to the pan and stir for 1 minute to lightly toast the grains and coat them in the aromatics.
Pour in the seafood stock and add the saffron threads, stirring once to distribute.
Bring the liquid to a gentle simmer, then nestle the cod pieces, shrimp, and mussels into the rice.
Reduce heat to low, cover the pan, and cook for 15-18 minutes without stirring until the rice is tender and the liquid is fully absorbed.
Scatter the frozen peas over the top during the last 2 minutes of cooking.
Remove from heat, season with sea salt, and let the paella rest for 5 minutes before serving with a fresh lemon wedge.