Heat the stock in a saucepan and add the saffron threads. Let it simmer on low heat to infuse the flavor.

In a large paella pan or wide skillet, heat olive oil over medium heat. Add the diced onion and sauté until translucent.

Add the minced garlic, grated tomato, and red bell pepper. Cook until the vegetables soften and the mixture thickens slightly.

Stir in the rice, coating it well with the vegetable mixture. Add smoked paprika, salt, and pepper.

Pour in the saffron-infused stock and bring to a gentle boil. Reduce heat and let it simmer without stirring for about 15 minutes.

Arrange the seafood (shrimp, mussels, clams, squid) on top of the rice. Cover and cook for another 10-12 minutes until the seafood is done.

Scatter the peas over the paella and cook for an additional 2 minutes. Remove from heat and let it rest for 5 minutes.

Garnish with fresh parsley and serve with lemon wedges on the side.