In a small bowl, crumble the saffron threads into the seafood stock and let them steep while you prep the other ingredients.
Heat the olive oil in a paella pan or wide skillet over medium heat.
Add the diced yellow onion and red bell pepper, sautéing until the onion is translucent and fragrant.
Stir in the minced garlic, smoked paprika, sea salt, and black pepper, cooking for 30 seconds until the spices bloom.
Add the tomato puree and Bomba rice, stirring well to ensure every grain is coated with the aromatic base.
Pour in the saffron-infused seafood stock and bring the mixture to a gentle simmer; do not stir the rice again to allow a crispy bottom layer to form.
After 10 minutes of simmering, tuck the mussels and shrimp into the rice, then sprinkle the green peas over the top.
Cover the pan and cook for 8-10 minutes until the mussels have opened, the shrimp are opaque, and the liquid is absorbed.
Garnish the dish with freshly chopped parsley and serve immediately with a bright lemon wedge.